--- /dev/null
+This is the Bash FAQ, version 3.24, for Bash version 2.05b.
+
+This document contains a set of frequently-asked questions concerning
+Bash, the GNU Bourne-Again Shell. Bash is a freely-available command
+interpreter with advanced features for both interactive use and shell
+programming.
+
+Another good source of basic information about shells is the collection
+of FAQ articles periodically posted to comp.unix.shell.
+
+Questions and comments concerning this document should be sent to
+chet@po.cwru.edu.
+
+This document is available for anonymous FTP with the URL
+
+ftp://ftp.cwru.edu/pub/bash/FAQ
+
+The Bash home page is http://cnswww.cns.cwru.edu/~chet/bash/bashtop.html
+
+----------
+Contents:
+
+Section A: The Basics
+
+A1) What is it?
+A2) What's the latest version?
+A3) Where can I get it?
+A4) On what machines will bash run?
+A5) Will bash run on operating systems other than Unix?
+A6) How can I build bash with gcc?
+A7) How can I make bash my login shell?
+A8) I just changed my login shell to bash, and now I can't FTP into my
+ machine. Why not?
+A9) What's the `POSIX 1003.2 standard'?
+A10) What is the bash `posix mode'?
+
+Section B: The latest version
+
+B1) What's new in version 2.05b?
+B2) Are there any user-visible incompatibilities between bash-2.05b and
+ bash-1.14.7?
+
+Section C: Differences from other Unix shells
+
+C1) How does bash differ from sh, the Bourne shell?
+C2) How does bash differ from the Korn shell, version ksh88?
+C3) Which new features in ksh-93 are not in bash, and which are?
+
+Section D: Why does bash do some things differently than other Unix shells?
+
+D1) Why does bash run a different version of `command' than
+ `which command' says it will?
+D2) Why doesn't bash treat brace expansions exactly like csh?
+D3) Why doesn't bash have csh variable modifiers?
+D4) How can I make my csh aliases work when I convert to bash?
+D5) How can I pipe standard output and standard error from one command to
+ another, like csh does with `|&'?
+D6) Now that I've converted from ksh to bash, are there equivalents to
+ ksh features like autoloaded functions and the `whence' command?
+
+Section E: Why does bash do certain things the way it does?
+
+E1) Why is the bash builtin `test' slightly different from /bin/test?
+E2) Why does bash sometimes say `Broken pipe'?
+E3) When I have terminal escape sequences in my prompt, why does bash
+ wrap lines at the wrong column?
+E4) If I pipe the output of a command into `read variable', why doesn't
+ the output show up in $variable when the read command finishes?
+E5) I have a bunch of shell scripts that use backslash-escaped characters
+ in arguments to `echo'. Bash doesn't interpret these characters. Why
+ not, and how can I make it understand them?
+E6) Why doesn't a while or for loop get suspended when I type ^Z?
+E7) What about empty for loops in Makefiles?
+E8) Why does the arithmetic evaluation code complain about `08'?
+E9) Why does the pattern matching expression [A-Z]* match files beginning
+ with every letter except `z'?
+E10) Why does `cd //' leave $PWD as `//'?
+E11) If I resize my xterm while another program is running, why doesn't bash
+ notice the change?
+
+Section F: Things to watch out for on certain Unix versions
+
+F1) Why can't I use command line editing in my `cmdtool'?
+F2) I built bash on Solaris 2. Why do globbing expansions and filename
+ completion chop off the first few characters of each filename?
+F3) Why does bash dump core after I interrupt username completion or
+ `~user' tilde expansion on a machine running NIS?
+F4) I'm running SVR4.2. Why is the line erased every time I type `@'?
+F5) Why does bash report syntax errors when my C News scripts use a
+ redirection before a subshell command?
+F6) Why can't I use vi-mode editing on Red Hat Linux 6.1?
+F7) Why do bash-2.05a and bash-2.05b fail to compile `printf.def' on
+ HP/UX 11.x?
+
+Section G: How can I get bash to do certain common things?
+
+G1) How can I get bash to read and display eight-bit characters?
+G2) How do I write a function `x' to replace builtin command `x', but
+ still invoke the command from within the function?
+G3) How can I find the value of a shell variable whose name is the value
+ of another shell variable?
+G4) How can I make the bash `time' reserved word print timing output that
+ looks like the output from my system's /usr/bin/time?
+G5) How do I get the current directory into my prompt?
+G6) How can I rename "*.foo" to "*.bar"?
+G7) How can I translate a filename from uppercase to lowercase?
+G8) How can I write a filename expansion (globbing) pattern that will match
+ all files in the current directory except "." and ".."?
+
+Section H: Where do I go from here?
+
+H1) How do I report bugs in bash, and where should I look for fixes and
+ advice?
+H2) What kind of bash documentation is there?
+H3) What's coming in future versions?
+H4) What's on the bash `wish list'?
+H5) When will the next release appear?
+
+----------
+Section A: The Basics
+
+A1) What is it?
+
+Bash is a Unix command interpreter (shell). It is an implementation of
+the Posix 1003.2 shell standard, and resembles the Korn and System V
+shells.
+
+Bash contains a number of enhancements over those shells, both
+for interactive use and shell programming. Features geared
+toward interactive use include command line editing, command
+history, job control, aliases, and prompt expansion. Programming
+features include additional variable expansions, shell
+arithmetic, and a number of variables and options to control
+shell behavior.
+
+Bash was originally written by Brian Fox of the Free Software
+Foundation. The current developer and maintainer is Chet Ramey
+of Case Western Reserve University.
+
+A2) What's the latest version?
+
+The latest version is 2.05b, first made available on Wednesday, 17
+July, 2002.
+
+A3) Where can I get it?
+
+Bash is the GNU project's shell, and so is available from the
+master GNU archive site, ftp.gnu.org, and its mirrors. The
+latest version is also available for FTP from ftp.cwru.edu.
+The following URLs tell how to get version 2.05b:
+
+ftp://ftp.gnu.org/pub/gnu/bash/bash-2.05b.tar.gz
+ftp://ftp.cwru.edu/pub/bash/bash-2.05b.tar.gz
+
+Formatted versions of the documentation are available with the URLs:
+
+ftp://ftp.gnu.org/pub/gnu/bash/bash-doc-2.05b.tar.gz
+ftp://ftp.cwru.edu/pub/bash/bash-doc-2.05b.tar.gz
+
+A4) On what machines will bash run?
+
+Bash has been ported to nearly every version of UNIX. All you
+should have to do to build it on a machine for which a port
+exists is to type `configure' and then `make'. The build process
+will attempt to discover the version of UNIX you have and tailor
+itself accordingly, using a script created by GNU autoconf.
+
+More information appears in the file `INSTALL' in the distribution.
+
+The Bash web page (http://cnswww.cns.cwru.edu/~chet/bash/bashtop.html)
+explains how to obtain binary versions of bash for most of the major
+commercial Unix systems.
+
+A5) Will bash run on operating systems other than Unix?
+
+Configuration specifics for Unix-like systems such as QNX and
+LynxOS are included in the distribution. Bash-2.05 and later
+versions should compile and run on Minix 2.0 (patches were
+contributed), but I don't believe anyone has built bash-2.x on
+earlier Minix versions yet.
+
+Bash has been ported to versions of Windows implementing the Win32
+programming interface. This includes Windows 95 and Windows NT.
+The port was done by Cygnus Solutions as part of their CYGWIN
+project. For more information about the project, look at the URLs
+
+http://www.cygwin.com/
+http://sourceware.cygnus.com/cygwin
+
+Cygnus originally ported bash-1.14.7, and that port was part of their
+early GNU-Win32 (the original name) releases. Cygnus has also done a
+port of bash-2.05 to the CYGWIN environment, and it is available as
+part of their current release.
+
+Bash-2.05b should require no local Cygnus changes to build and run under
+CYGWIN.
+
+The Cygnus port works only on Intel machines. There is a port of bash
+(I don't know which version) to the alpha/NT environment available from
+
+ftp://ftp.gnustep.org//pub/win32/bash-alpha-nt-1.01.tar.gz
+
+DJ Delorie has a port of bash-2.x which runs under MS-DOS, as part
+of the DJGPP project. For more information on the project, see
+
+http://www.delorie.com/djgpp/
+
+I have been told that the original DJGPP port was done by Daisuke Aoyama.
+
+Mark Elbrecht <snowball3@bigfoot.com> has sent me notice that bash-2.04
+is available for DJGPP V2. The files are available as:
+
+ftp://ftp.simtel.net/pub/simtelnet/gnu/djgpp/v2gnu/bsh204b.zip binary
+ftp://ftp.simtel.net/pub/simtelnet/gnu/djgpp/v2gnu/bsh204d.zip documentation
+ftp://ftp.simtel.net/pub/simtelnet/gnu/djgpp/v2gnu/bsh204s.zip source
+
+Mark has begun to work with bash-2.05, but I don't know the status.
+
+Ports of bash-1.12 and bash-2.0 are available for OS/2 from
+
+ftp://hobbes.nmsu.edu/pub/os2/util/shell/bash_112.zip
+ftp://hobbes.nmsu.edu/pub/os2/util/shell/bash-2.0(253).zip
+
+I haven't looked at either, but the second appears to be a binary-only
+distribution. Beware.
+
+I have received word that Bash (I'm not sure which version, but I
+believe that it's at least bash-2.02.1) is the standard shell on
+BeOS.
+
+A6) How can I build bash with gcc?
+
+Bash configures to use gcc by default if it is available. Read the
+file INSTALL in the distribution for more information.
+
+A7) How can I make bash my login shell?
+
+Some machines let you use `chsh' to change your login shell. Other
+systems use `passwd -s' or `passwd -e'. If one of these works for
+you, that's all you need. Note that many systems require the full
+pathname to a shell to appear in /etc/shells before you can make it
+your login shell. For this, you may need the assistance of your
+friendly local system administrator.
+
+If you cannot do this, you can still use bash as your login shell, but
+you need to perform some tricks. The basic idea is to add a command
+to your login shell's startup file to replace your login shell with
+bash.
+
+For example, if your login shell is csh or tcsh, and you have installed
+bash in /usr/gnu/bin/bash, add the following line to ~/.login:
+
+ if ( -f /usr/gnu/bin/bash ) exec /usr/gnu/bin/bash --login
+
+(the `--login' tells bash that it is a login shell).
+
+It's not a good idea to put this command into ~/.cshrc, because every
+csh you run without the `-f' option, even ones started to run csh scripts,
+reads that file. If you must put the command in ~/.cshrc, use something
+like
+
+ if ( $?prompt ) exec /usr/gnu/bin/bash --login
+
+to ensure that bash is exec'd only when the csh is interactive.
+
+If your login shell is sh or ksh, you have to do two things.
+
+First, create an empty file in your home directory named `.bash_profile'.
+The existence of this file will prevent the exec'd bash from trying to
+read ~/.profile, and re-execing itself over and over again. ~/.bash_profile
+is the first file bash tries to read initialization commands from when
+it is invoked as a login shell.
+
+Next, add a line similar to the above to ~/.profile:
+
+ [ -f /usr/gnu/bin/bash ] && [ -x /usr/gnu/bin/bash ] && \
+ exec /usr/gnu/bin/bash --login
+
+This will cause login shells to replace themselves with bash running as
+a login shell. Once you have this working, you can copy your initialization
+code from ~/.profile to ~/.bash_profile.
+
+I have received word that the recipe supplied above is insufficient for
+machines running CDE. CDE has a maze of twisty little startup files, all
+slightly different.
+
+If you cannot change your login shell in the password file to bash, you
+will have to (apparently) live with CDE using the shell in the password
+file to run its startup scripts. If you have changed your shell to bash,
+there is code in the CDE startup files (on Solaris, at least) that attempts
+to do the right thing. It is, however, often broken, and may require that
+you use the $BASH_ENV trick described below.
+
+`dtterm' claims to use $SHELL as the default program to start, so if you
+can change $SHELL in the CDE startup files, you should be able to use bash
+in your terminal windows.
+
+Setting DTSOURCEPROFILE in ~/.dtprofile will cause the `Xsession' program
+to read your login shell's startup files. You may be able to use bash for
+the rest of the CDE programs by setting SHELL to bash in ~/.dtprofile as
+well, but I have not tried this.
+
+You can use the above `exec' recipe to start bash when not logging in with
+CDE by testing the value of the DT variable:
+
+ if [ -n "$DT" ]; then
+ [ -f /usr/gnu/bin/bash ] && exec /usr/gnu/bin/bash --login
+ fi
+
+If CDE starts its shells non-interactively during login, the login shell
+startup files (~/.profile, ~/.bash_profile) will not be sourced at login.
+To get around this problem, append a line similar to the following to your
+~/.dtprofile:
+
+ BASH_ENV=${HOME}/.bash_profile ; export BASH_ENV
+
+and add the following line to the beginning of ~/.bash_profile:
+
+ unset BASH_ENV
+
+A8) I just changed my login shell to bash, and now I can't FTP into my
+ machine. Why not?
+
+You must add the full pathname to bash to the file /etc/shells. As
+noted in the answer to the previous question, many systems require
+this before you can make bash your login shell.
+
+Most versions of ftpd use this file to prohibit `special' users
+such as `uucp' and `news' from using FTP.
+
+A9) What's the `POSIX 1003.2 standard'?
+
+POSIX is a name originally coined by Richard Stallman for a
+family of open system standards based on UNIX. There are a
+number of aspects of UNIX under consideration for
+standardization, from the basic system services at the system
+call and C library level to applications and tools to system
+administration and management. Each area of standardization is
+assigned to a working group in the 1003 series.
+
+The POSIX Shell and Utilities standard has been developed by IEEE
+Working Group 1003.2 (POSIX.2). It concentrates on the command
+interpreter interface and utility programs commonly executed from
+the command line or by other programs. An initial version of the
+standard has been approved and published by the IEEE, and work is
+currently underway to update it.
+
+Bash is concerned with the aspects of the shell's behavior
+defined by POSIX.2. The shell command language has of course
+been standardized, including the basic flow control and program
+execution constructs, I/O redirection and pipelining, argument
+handling, variable expansion, and quoting.
+
+The `special' builtins, which must be implemented as part of the
+shell to provide the desired functionality, are specified as
+being part of the shell; examples of these are `eval' and
+`export'. Other utilities appear in the sections of POSIX.2 not
+devoted to the shell which are commonly (and in some cases must
+be) implemented as builtin commands, such as `read' and `test'.
+POSIX.2 also specifies aspects of the shell's interactive
+behavior as part of the UPE, including job control and command
+line editing. Only vi-style line editing commands have been
+standardized; emacs editing commands were left out due to
+objections.
+
+The Open Group has made an older version of its Single Unix
+Specification (version 2), which is very similar to POSIX.2,
+available on the web at
+
+http://www.opengroup.org/onlinepubs/007908799/
+
+The Single Unix Specification, version 3, is available on the web at
+
+http://www.opengroup.org/onlinepubs/007904975/
+
+A10) What is the bash `posix mode'?
+
+Although bash is an implementation of the POSIX.2 shell
+specification, there are areas where the bash default behavior
+differs from that spec. The bash `posix mode' changes the bash
+behavior in these areas so that it obeys the spec more closely.
+
+Posix mode is entered by starting bash with the --posix or
+'-o posix' option or executing `set -o posix' after bash is running.
+
+The specific aspects of bash which change when posix mode is
+active are listed in the file POSIX in the bash distribution.
+They are also listed in a section in the Bash Reference Manual
+(from which that file is generated).
+
+Section B: The latest version
+
+B1) What's new in version 2.05b?
+
+The raison d'etre for bash-2.05b is to make a second intermediate
+release containing the first of the new features to be available
+in bash-3.0 and get feedback on those features before proceeding.
+The major new feature is multibyte character support in both Bash
+and Readline.
+
+Bash-2.05b contains the following new features (see the manual page for
+complete descriptions and the CHANGES and NEWS files in the bash-2.05b
+distribution):
+
+o support for multibyte characters has been added to both bash and readline
+
+o the DEBUG trap is now run *before* simple commands, ((...)) commands,
+ [[...]] conditional commands, and for ((...)) loops
+
+o the shell now performs arithmetic in the largest integer size the machine
+ supports (intmax_t)
+
+o there is a new \D{...} prompt expansion; passes the `...' to strftime(3)
+ and inserts the result into the expanded prompt
+
+o there is a new `here-string' redirection operator: <<< word
+
+o when displaying variables, function attributes and definitions are shown
+ separately, allowing them to be re-used as input (attempting to re-use
+ the old output would result in syntax errors).
+
+o `read' has a new `-u fd' option to read from a specified file descriptor
+
+o the bash debugger in examples/bashdb has been modified to work with the
+ new DEBUG trap semantics, the command set has been made more gdb-like,
+ and the changes to $LINENO make debugging functions work better
+
+o the expansion of $LINENO inside a shell function is only relative to the
+ function start if the shell is interactive -- if the shell is running a
+ script, $LINENO expands to the line number in the script. This is as
+ POSIX-2001 requires
+
+
+A short feature history dating from Bash-2.0:
+
+Bash-2.05a introduced the following new features:
+
+o The `printf' builtin has undergone major work
+
+o There is a new read-only `shopt' option: login_shell, which is set by
+ login shells and unset otherwise
+
+o New `\A' prompt string escape sequence; expanding to time in 24-hour
+ HH:MM format
+
+o New `-A group/-g' option to complete and compgen; goes group name
+ completion
+
+o New [+-]O invocation option to set and unset `shopt' options at startup
+
+o ksh-like `ERR' trap
+
+o `for' loops now allow empty word lists after the `in' reserved word
+
+o new `hard' and `soft' arguments for the `ulimit' builtin
+
+o Readline can be configured to place the user at the same point on the line
+ when retrieving commands from the history list
+
+o Readline can be configured to skip `hidden' files (filenames with a leading
+ `.' on Unix) when performing completion
+
+Bash-2.05 introduced the following new features:
+
+o This version has once again reverted to using locales and strcoll(3) when
+ processing pattern matching bracket expressions, as POSIX requires.
+o Added a new `--init-file' invocation argument as a synonym for `--rcfile',
+ per the new GNU coding standards.
+o The /dev/tcp and /dev/udp redirections now accept service names as well as
+ port numbers.
+o `complete' and `compgen' now take a `-o value' option, which controls some
+ of the aspects of that compspec. Valid values are:
+
+ default - perform bash default completion if programmable
+ completion produces no matches
+ dirnames - perform directory name completion if programmable
+ completion produces no matches
+ filenames - tell readline that the compspec produces filenames,
+ so it can do things like append slashes to
+ directory names and suppress trailing spaces
+o A new loadable builtin, realpath, which canonicalizes and expands symlinks
+ in pathname arguments.
+o When `set' is called without options, it prints function defintions in a
+ way that allows them to be reused as input. This affects `declare' and
+ `declare -p' as well. This only happens when the shell is not in POSIX
+ mode, since POSIX.2 forbids this behavior.
+
+Bash-2.04 introduced the following new features:
+
+o Programmable word completion with the new `complete' and `compgen' builtins;
+ examples are provided in examples/complete/complete-examples
+o `history' has a new `-d' option to delete a history entry
+o `bind' has a new `-x' option to bind key sequences to shell commands
+o The prompt expansion code has new `\j' and `\l' escape sequences
+o The `no_empty_cmd_completion' shell option, if enabled, inhibits
+ command completion when TAB is typed on an empty line
+o `help' has a new `-s' option to print a usage synopsis
+o New arithmetic operators: var++, var--, ++var, --var, expr1,expr2 (comma)
+o New ksh93-style arithmetic for command:
+ for ((expr1 ; expr2; expr3 )); do list; done
+o `read' has new options: `-t', `-n', `-d', `-s'
+o The redirection code handles several filenames specially: /dev/fd/N,
+ /dev/stdin, /dev/stdout, /dev/stderr
+o The redirection code now recognizes /dev/tcp/HOST/PORT and
+ /dev/udp/HOST/PORT and tries to open a TCP or UDP socket, respectively,
+ to the specified port on the specified host
+o The ${!prefix*} expansion has been implemented
+o A new FUNCNAME variable, which expands to the name of a currently-executing
+ function
+o The GROUPS variable is no longer readonly
+o A new shopt `xpg_echo' variable, to control the behavior of echo with
+ respect to backslash-escape sequences at runtime
+o The NON_INTERACTIVE_LOGIN_SHELLS #define has returned
+
+The version of Readline released with Bash-2.04, Readline-4.1, had several
+new features as well:
+
+o Parentheses matching is always compiled into readline, and controllable
+ with the new `blink-matching-paren' variable
+o The history-search-forward and history-search-backward functions now leave
+ point at the end of the line when the search string is empty, like
+ reverse-search-history, and forward-search-history
+o A new function for applications: rl_on_new_line_with_prompt()
+o New variables for applications: rl_already_prompted, and rl_gnu_readline_p
+
+
+Bash-2.03 had very few new features, in keeping with the convention
+that odd-numbered releases provide mainly bug fixes. A number of new
+features were added to Readline, mostly at the request of the Cygnus
+folks.
+
+A new shopt option, `restricted_shell', so that startup files can test
+ whether or not the shell was started in restricted mode
+Filename generation is now performed on the words between ( and ) in
+ compound array assignments (this is really a bug fix)
+OLDPWD is now auto-exported, as POSIX.2 requires
+ENV and BASH_ENV are read-only variables in a restricted shell
+Bash may now be linked against an already-installed Readline library,
+ as long as the Readline library is version 4 or newer
+All shells begun with the `--login' option will source the login shell
+ startup files, even if the shell is not interactive
+
+There were lots of changes to the version of the Readline library released
+along with Bash-2.03. For a complete list of the changes, read the file
+CHANGES in the Bash-2.03 distribution.
+
+Bash-2.02 contained the following new features:
+
+a new version of malloc (based on the old GNU malloc code in previous
+ bash versions) that is more page-oriented, more conservative
+ with memory usage, does not `orphan' large blocks when they
+ are freed, is usable on 64-bit machines, and has allocation
+ checking turned on unconditionally
+POSIX.2-style globbing character classes ([:alpha:], [:alnum:], etc.)
+POSIX.2-style globbing equivalence classes
+POSIX.2-style globbing collating symbols
+the ksh [[...]] extended conditional command
+the ksh egrep-style extended pattern matching operators
+a new `printf' builtin
+the ksh-like $(<filename) command substitution, which is equivalent to
+ $(cat filename)
+new tilde prefixes that expand to directories from the directory stack
+new `**' arithmetic operator to do exponentiation
+case-insensitive globbing (filename expansion)
+menu completion a la tcsh
+`magic-space' history expansion function like tcsh
+the readline inputrc `language' has a new file inclusion directive ($include)
+
+Bash-2.01 contained only a few new features:
+
+new `GROUPS' builtin array variable containing the user's group list
+new bindable readline commands: history-and-alias-expand-line and
+ alias-expand-line
+
+Bash-2.0 contained extensive changes and new features from bash-1.14.7.
+Here's a short list:
+
+new `time' reserved word to time pipelines, shell builtins, and
+ shell functions
+one-dimensional arrays with a new compound assignment statement,
+ appropriate expansion constructs and modifications to some
+ of the builtins (read, declare, etc.) to use them
+new quoting syntaxes for ANSI-C string expansion and locale-specific
+ string translation
+new expansions to do substring extraction, pattern replacement, and
+ indirect variable expansion
+new builtins: `disown' and `shopt'
+new variables: HISTIGNORE, SHELLOPTS, PIPESTATUS, DIRSTACK, GLOBIGNORE,
+ MACHTYPE, BASH_VERSINFO
+special handling of many unused or redundant variables removed
+ (e.g., $notify, $glob_dot_filenames, $no_exit_on_failed_exec)
+dynamic loading of new builtin commands; many loadable examples provided
+new prompt expansions: \a, \e, \n, \H, \T, \@, \v, \V
+history and aliases available in shell scripts
+new readline variables: enable-keypad, mark-directories, input-meta,
+ visible-stats, disable-completion, comment-begin
+new readline commands to manipulate the mark and operate on the region
+new readline emacs mode commands and bindings for ksh-88 compatibility
+updated and extended builtins
+new DEBUG trap
+expanded (and now documented) restricted shell mode
+
+implementation stuff:
+autoconf-based configuration
+nearly all of the bugs reported since version 1.14 have been fixed
+most builtins converted to use builtin `getopt' for consistency
+most builtins use -p option to display output in a reusable form
+ (for consistency)
+grammar tighter and smaller (66 reduce-reduce conflicts gone)
+lots of code now smaller and faster
+test suite greatly expanded
+
+B2) Are there any user-visible incompatibilities between bash-2.05b and
+ bash-1.14.7?
+
+There are a few incompatibilities between version 1.14.7 and version 2.05b.
+They are detailed in the file COMPAT in the bash distribution. That file
+is not meant to be all-encompassing; send mail to bash-maintainers@gnu.org
+if if you find something that's not mentioned there.
+
+Section C: Differences from other Unix shells
+
+C1) How does bash differ from sh, the Bourne shell?
+
+This is a non-comprehensive list of features that differentiate bash
+from the SVR4.2 shell. The bash manual page explains these more
+completely.
+
+Things bash has that sh does not:
+ long invocation options
+ [+-]O invocation option
+ -l invocation option
+ `!' reserved word to invert pipeline return value
+ `time' reserved word to time pipelines and shell builtins
+ the `function' reserved word
+ the `select' compound command and reserved word
+ arithmetic for command: for ((expr1 ; expr2; expr3 )); do list; done
+ new $'...' and $"..." quoting
+ the $(...) form of command substitution
+ the $(<filename) form of command substitution, equivalent to
+ $(cat filename)
+ the ${#param} parameter value length operator
+ the ${!param} indirect parameter expansion operator
+ the ${!param*} prefix expansion operator
+ the ${param:offset[:length]} parameter substring operator
+ the ${param/pat[/string]} parameter pattern substitution operator
+ expansions to perform substring removal (${p%[%]w}, ${p#[#]w})
+ expansion of positional parameters beyond $9 with ${num}
+ variables: BASH, BASH_VERSION, BASH_VERSINFO, UID, EUID, REPLY,
+ TIMEFORMAT, PPID, PWD, OLDPWD, SHLVL, RANDOM, SECONDS,
+ LINENO, HISTCMD, HOSTTYPE, OSTYPE, MACHTYPE, HOSTNAME,
+ ENV, PS3, PS4, DIRSTACK, PIPESTATUS, HISTSIZE, HISTFILE,
+ HISTFILESIZE, HISTCONTROL, HISTIGNORE, GLOBIGNORE, GROUPS,
+ PROMPT_COMMAND, FCEDIT, FIGNORE, IGNOREEOF, INPUTRC,
+ SHELLOPTS, OPTERR, HOSTFILE, TMOUT, FUNCNAME, histchars,
+ auto_resume
+ DEBUG trap
+ ERR trap
+ variable arrays with new compound assignment syntax
+ redirections: <>, &>, >|, <<<, [n]<&word-, [n]>&word-
+ prompt string special char translation and variable expansion
+ auto-export of variables in initial environment
+ command search finds functions before builtins
+ bash return builtin will exit a file sourced with `.'
+ builtins: cd -/-L/-P, exec -l/-c/-a, echo -e/-E, hash -d/-l/-p/-t.
+ export -n/-f/-p/name=value, pwd -L/-P,
+ read -e/-p/-a/-t/-n/-d/-s/-u,
+ readonly -a/-f/name=value, trap -l, set +o,
+ set -b/-m/-o option/-h/-p/-B/-C/-H/-P,
+ unset -f/-v, ulimit -m/-p/-u,
+ type -a/-p/-t/-f/-P, suspend -f, kill -n,
+ test -o optname/s1 == s2/s1 < s2/s1 > s2/-nt/-ot/-ef/-O/-G/-S
+ bash reads ~/.bashrc for interactive shells, $ENV for non-interactive
+ bash restricted shell mode is more extensive
+ bash allows functions and variables with the same name
+ brace expansion
+ tilde expansion
+ arithmetic expansion with $((...)) and `let' builtin
+ the `[[...]]' extended conditional command
+ process substitution
+ aliases and alias/unalias builtins
+ local variables in functions and `local' builtin
+ readline and command-line editing with programmable completion
+ command history and history/fc builtins
+ csh-like history expansion
+ other new bash builtins: bind, command, compgen, complete, builtin,
+ declare/typeset, dirs, enable, fc, help,
+ history, logout, popd, pushd, disown, shopt,
+ printf
+ exported functions
+ filename generation when using output redirection (command >a*)
+ POSIX.2-style globbing character classes
+ POSIX.2-style globbing equivalence classes
+ POSIX.2-style globbing collating symbols
+ egrep-like extended pattern matching operators
+ case-insensitive pattern matching and globbing
+ variable assignments preceding commands affect only that command,
+ even for builtins and functions
+ posix mode
+ redirection to /dev/fd/N, /dev/stdin, /dev/stdout, /dev/stderr,
+ /dev/tcp/host/port, /dev/udp/host/port
+
+Things sh has that bash does not:
+ uses variable SHACCT to do shell accounting
+ includes `stop' builtin (bash can use alias stop='kill -s STOP')
+ `newgrp' builtin
+ turns on job control if called as `jsh'
+ $TIMEOUT (like bash $TMOUT)
+ `^' is a synonym for `|'
+ new SVR4.2 sh builtins: mldmode, priv
+
+Implementation differences:
+ redirection to/from compound commands causes sh to create a subshell
+ bash does not allow unbalanced quotes; sh silently inserts them at EOF
+ bash does not mess with signal 11
+ sh sets (euid, egid) to (uid, gid) if -p not supplied and uid < 100
+ bash splits only the results of expansions on IFS, using POSIX.2
+ field splitting rules; sh splits all words on IFS
+ sh does not allow MAILCHECK to be unset (?)
+ sh does not allow traps on SIGALRM or SIGCHLD
+ bash allows multiple option arguments when invoked (e.g. -x -v);
+ sh allows only a single option argument (`sh -x -v' attempts
+ to open a file named `-v', and, on SunOS 4.1.4, dumps core.
+ On Solaris 2.4 and earlier versions, sh goes into an infinite
+ loop.)
+ sh exits a script if any builtin fails; bash exits only if one of
+ the POSIX.2 `special' builtins fails
+
+C2) How does bash differ from the Korn shell, version ksh88?
+
+Things bash has or uses that ksh88 does not:
+ long invocation options
+ [-+]O invocation option
+ -l invocation option
+ `!' reserved word
+ arithmetic for command: for ((expr1 ; expr2; expr3 )); do list; done
+ arithmetic in largest machine-supported size (intmax_t)
+ posix mode and posix conformance
+ command hashing
+ tilde expansion for assignment statements that look like $PATH
+ process substitution with named pipes if /dev/fd is not available
+ the ${!param} indirect parameter expansion operator
+ the ${!param*} prefix expansion operator
+ the ${param:offset[:length]} parameter substring operator
+ the ${param/pat[/string]} parameter pattern substitution operator
+ variables: BASH, BASH_VERSION, BASH_VERSINFO, UID, EUID, SHLVL,
+ TIMEFORMAT, HISTCMD, HOSTTYPE, OSTYPE, MACHTYPE,
+ HISTFILESIZE, HISTIGNORE, HISTCONTROL, PROMPT_COMMAND,
+ IGNOREEOF, FIGNORE, INPUTRC, HOSTFILE, DIRSTACK,
+ PIPESTATUS, HOSTNAME, OPTERR, SHELLOPTS, GLOBIGNORE,
+ GROUPS, FUNCNAME, histchars, auto_resume
+ prompt expansion with backslash escapes and command substitution
+ redirection: &> (stdout and stderr), <<<, [n]<&word-, [n]>&word-
+ more extensive and extensible editing and programmable completion
+ builtins: bind, builtin, command, declare, dirs, echo -e/-E, enable,
+ exec -l/-c/-a, fc -s, export -n/-f/-p, hash, help, history,
+ jobs -x/-r/-s, kill -s/-n/-l, local, logout, popd, pushd,
+ read -e/-p/-a/-t/-n/-d/-s, readonly -a/-n/-f/-p,
+ set -o braceexpand/-o histexpand/-o interactive-comments/
+ -o notify/-o physical/-o posix/-o hashall/-o onecmd/
+ -h/-B/-C/-b/-H/-P, set +o, suspend, trap -l, type,
+ typeset -a/-F/-p, ulimit -u, umask -S, alias -p, shopt,
+ disown, printf, complete, compgen
+ `!' csh-style history expansion
+ POSIX.2-style globbing character classes
+ POSIX.2-style globbing equivalence classes
+ POSIX.2-style globbing collating symbols
+ egrep-like extended pattern matching operators
+ case-insensitive pattern matching and globbing
+ `**' arithmetic operator to do exponentiation
+ redirection to /dev/fd/N, /dev/stdin, /dev/stdout, /dev/stderr
+ arrays of unlimited size
+ TMOUT is default timeout for `read' and `select'
+
+Things ksh88 has or uses that bash does not:
+ tracked aliases (alias -t)
+ variables: ERRNO, FPATH, EDITOR, VISUAL
+ co-processes (|&, >&p, <&p)
+ weirdly-scoped functions
+ typeset +f to list all function names without definitions
+ text of command history kept in a file, not memory
+ builtins: alias -x, cd old new, fc -e -, newgrp, print,
+ read -p/-s/var?prompt, set -A/-o gmacs/
+ -o bgnice/-o markdirs/-o nolog/-o trackall/-o viraw/-s,
+ typeset -H/-L/-R/-Z/-A/-ft/-fu/-fx/-l/-u/-t, whence
+ using environment to pass attributes of exported variables
+ arithmetic evaluation done on arguments to some builtins
+ reads .profile from $PWD when invoked as login shell
+
+Implementation differences:
+ ksh runs last command of a pipeline in parent shell context
+ bash has brace expansion by default (ksh88 compile-time option)
+ bash has fixed startup file for all interactive shells; ksh reads $ENV
+ bash has exported functions
+ bash command search finds functions before builtins
+ bash waits for all commands in pipeline to exit before returning status
+ emacs-mode editing has some slightly different key bindings
+
+C3) Which new features in ksh-93 are not in bash, and which are?
+
+New things in ksh-93 not in bash-2.05b:
+ associative arrays
+ floating point arithmetic and variables
+ math library functions
+ ${!name[sub]} name of subscript for associative array
+ `.' is allowed in variable names to create a hierarchical namespace
+ more extensive compound assignment syntax
+ discipline functions
+ `sleep' and `getconf' builtins (bash has loadable versions)
+ typeset -n and `nameref' variables
+ KEYBD trap
+ variables: .sh.edchar, .sh.edmode, .sh.edcol, .sh.edtext, .sh.version,
+ .sh.name, .sh.subscript, .sh.value, .sh.match, HISTEDIT
+ backreferences in pattern matching (\N)
+ `&' operator in pattern lists for matching
+ print -f (bash uses printf)
+ `fc' has been renamed to `hist'
+ `.' can execute shell functions
+ exit statuses between 0 and 255
+ set -o pipefail
+ `+=' variable assignment operator
+ FPATH and PATH mixing
+ getopts -a
+ -I invocation option
+ DEBUG trap now executed before each simple command, instead of after
+ printf %H, %P, %T, %Z modifiers, output base for %d
+ lexical scoping for local variables in `ksh' functions
+ no scoping for local variables in `POSIX' functions
+
+New things in ksh-93 present in bash-2.05b:
+ [n]<&word- and [n]>&word- redirections (combination dup and close)
+ for (( expr1; expr2; expr3 )) ; do list; done - arithmetic for command
+ ?:, ++, --, `expr1 , expr2' arithmetic operators
+ expansions: ${!param}, ${param:offset[:len]}, ${param/pat[/str]},
+ ${!param*}
+ compound array assignment
+ the `!' reserved word
+ loadable builtins -- but ksh uses `builtin' while bash uses `enable'
+ `command', `builtin', `disown' builtins
+ new $'...' and $"..." quoting
+ FIGNORE (but bash uses GLOBIGNORE), HISTCMD
+ set -o notify/-C
+ changes to kill builtin
+ read -A (bash uses read -a)
+ read -t/-d
+ trap -p
+ exec -c/-a
+ `.' restores the positional parameters when it completes
+ POSIX.2 `test'
+ umask -S
+ unalias -a
+ command and arithmetic substitution performed on PS1, PS4, and ENV
+ command name completion
+ ENV processed only for interactive shells
+
+Section D: Why does bash do some things differently than other Unix shells?
+
+D1) Why does bash run a different version of `command' than
+ `which command' says it will?
+
+On many systems, `which' is actually a csh script that assumes
+you're running csh. In tcsh, `which' and its cousin `where'
+are builtins. On other Unix systems, `which' is a perl script
+that uses the PATH environment variable.
+
+The csh script version reads the csh startup files from your
+home directory and uses those to determine which `command' will
+be invoked. Since bash doesn't use any of those startup files,
+there's a good chance that your bash environment differs from
+your csh environment. The bash `type' builtin does everything
+`which' does, and will report correct results for the running
+shell. If you're really wedded to the name `which', try adding
+the following function definition to your .bashrc:
+
+ which()
+ {
+ builtin type "$@"
+ }
+
+If you're moving from tcsh and would like to bring `where' along
+as well, use this function:
+
+ where()
+ {
+ builtin type -a "$@"
+ }
+
+D2) Why doesn't bash treat brace expansions exactly like csh?
+
+The only difference between bash and csh brace expansion is that
+bash requires a brace expression to contain at least one unquoted
+comma if it is to be expanded. Any brace-surrounded word not
+containing an unquoted comma is left unchanged by the brace
+expansion code. This affords the greatest degree of sh
+compatibility.
+
+Bash, ksh, zsh, and pd-ksh all implement brace expansion this way.
+
+D3) Why doesn't bash have csh variable modifiers?
+
+Posix has specified a more powerful, albeit somewhat more cryptic,
+mechanism cribbed from ksh, and bash implements it.
+
+${parameter%word}
+ Remove smallest suffix pattern. The WORD is expanded to produce
+ a pattern. It then expands to the value of PARAMETER, with the
+ smallest portion of the suffix matched by the pattern deleted.
+
+ x=file.c
+ echo ${x%.c}.o
+ -->file.o
+
+${parameter%%word}
+
+ Remove largest suffix pattern. The WORD is expanded to produce
+ a pattern. It then expands to the value of PARAMETER, with the
+ largest portion of the suffix matched by the pattern deleted.
+
+ x=posix/src/std
+ echo ${x%%/*}
+ -->posix
+
+${parameter#word}
+ Remove smallest prefix pattern. The WORD is expanded to produce
+ a pattern. It then expands to the value of PARAMETER, with the
+ smallest portion of the prefix matched by the pattern deleted.
+
+ x=$HOME/src/cmd
+ echo ${x#$HOME}
+ -->/src/cmd
+
+${parameter##word}
+ Remove largest prefix pattern. The WORD is expanded to produce
+ a pattern. It then expands to the value of PARAMETER, with the
+ largest portion of the prefix matched by the pattern deleted.
+
+ x=/one/two/three
+ echo ${x##*/}
+ -->three
+
+
+Given
+ a=/a/b/c/d
+ b=b.xxx
+
+ csh bash result
+ --- ---- ------
+ $a:h ${a%/*} /a/b/c
+ $a:t ${a##*/} d
+ $b:r ${b%.*} b
+ $b:e ${b##*.} xxx
+
+
+D4) How can I make my csh aliases work when I convert to bash?
+
+Bash uses a different syntax to support aliases than csh does.
+The details can be found in the documentation. We have provided
+a shell script which does most of the work of conversion for you;
+this script can be found in ./examples/misc/aliasconv.sh. Here is
+how you use it:
+
+Start csh in the normal way for you. (e.g., `csh')
+
+Pipe the output of `alias' through `aliasconv.sh', saving the
+results into `bash_aliases':
+
+ alias | bash aliasconv.sh >bash_aliases
+
+Edit `bash_aliases', carefully reading through any created
+functions. You will need to change the names of some csh specific
+variables to the bash equivalents. The script converts $cwd to
+$PWD, $term to $TERM, $home to $HOME, $user to $USER, and $prompt
+to $PS1. You may also have to add quotes to avoid unwanted
+expansion.
+
+For example, the csh alias:
+
+ alias cd 'cd \!*; echo $cwd'
+
+is converted to the bash function:
+
+ cd () { command cd "$@"; echo $PWD ; }
+
+The only thing that needs to be done is to quote $PWD:
+
+ cd () { command cd "$@"; echo "$PWD" ; }
+
+Merge the edited file into your ~/.bashrc.
+
+There is an additional, more ambitious, script in
+examples/misc/cshtobash that attempts to convert your entire csh
+environment to its bash equivalent. This script can be run as
+simply `cshtobash' to convert your normal interactive
+environment, or as `cshtobash ~/.login' to convert your login
+environment.
+
+D5) How can I pipe standard output and standard error from one command to
+ another, like csh does with `|&'?
+
+Use
+ command 2>&1 | command2
+
+The key is to remember that piping is performed before redirection, so
+file descriptor 1 points to the pipe when it is duplicated onto file
+descriptor 2.
+
+D6) Now that I've converted from ksh to bash, are there equivalents to
+ ksh features like autoloaded functions and the `whence' command?
+
+There are features in ksh-88 and ksh-93 that do not have direct bash
+equivalents. Most, however, can be emulated with very little trouble.
+
+ksh-88 feature Bash equivalent
+-------------- ---------------
+compiled-in aliases set up aliases in .bashrc; some ksh aliases are
+ bash builtins (hash, history, type)
+coprocesses named pipe pairs (one for read, one for write)
+typeset +f declare -F
+cd, print, whence function substitutes in examples/functions/kshenv
+autoloaded functions examples/functions/autoload is the same as typeset -fu
+read var?prompt read -p prompt var
+
+ksh-93 feature Bash equivalent
+-------------- ---------------
+sleep, getconf Bash has loadable versions in examples/loadables
+${.sh.version} $BASH_VERSION
+print -f printf
+hist alias hist=fc
+$HISTEDIT $FCEDIT
+
+Section E: How can I get bash to do certain things, and why does bash do
+ things the way it does?
+
+E1) Why is the bash builtin `test' slightly different from /bin/test?
+
+The specific example used here is [ ! x -o x ], which is false.
+
+Bash's builtin `test' implements the Posix.2 spec, which can be
+summarized as follows (the wording is due to David Korn):
+
+Here is the set of rules for processing test arguments.
+
+ 0 Args: False
+ 1 Arg: True iff argument is not null.
+ 2 Args: If first arg is !, True iff second argument is null.
+ If first argument is unary, then true if unary test is true
+ Otherwise error.
+ 3 Args: If second argument is a binary operator, do binary test of $1 $3
+ If first argument is !, negate two argument test of $2 $3
+ If first argument is `(' and third argument is `)', do the
+ one-argument test of the second argument.
+ Otherwise error.
+ 4 Args: If first argument is !, negate three argument test of $2 $3 $4.
+ Otherwise unspecified
+ 5 or more Args: unspecified. (Historical shells would use their
+ current algorithm).
+
+The operators -a and -o are considered binary operators for the purpose
+of the 3 Arg case.
+
+As you can see, the test becomes (not (x or x)), which is false.
+
+E2) Why does bash sometimes say `Broken pipe'?
+
+If a sequence of commands appears in a pipeline, and one of the
+reading commands finishes before the writer has finished, the
+writer receives a SIGPIPE signal. Many other shells special-case
+SIGPIPE as an exit status in the pipeline and do not report it.
+For example, in:
+
+ ps -aux | head
+
+`head' can finish before `ps' writes all of its output, and ps
+will try to write on a pipe without a reader. In that case, bash
+will print `Broken pipe' to stderr when ps is killed by a
+SIGPIPE.
+
+You can build a version of bash that will not report SIGPIPE errors
+by uncommenting the definition of DONT_REPORT_SIGPIPE in the file
+config-top.h.
+
+E3) When I have terminal escape sequences in my prompt, why does bash
+ wrap lines at the wrong column?
+
+Readline, the line editing library that bash uses, does not know
+that the terminal escape sequences do not take up space on the
+screen. The redisplay code assumes, unless told otherwise, that
+each character in the prompt is a `printable' character that
+takes up one character position on the screen.
+
+You can use the bash prompt expansion facility (see the PROMPTING
+section in the manual page) to tell readline that sequences of
+characters in the prompt strings take up no screen space.
+
+Use the \[ escape to begin a sequence of non-printing characters,
+and the \] escape to signal the end of such a sequence.
+
+E4) If I pipe the output of a command into `read variable', why doesn't
+ the output show up in $variable when the read command finishes?
+
+This has to do with the parent-child relationship between Unix
+processes. It affects all commands run in pipelines, not just
+simple calls to `read'. For example, piping a command's output
+into a `while' loop that repeatedly calls `read' will result in
+the same behavior.
+
+Each element of a pipeline runs in a separate process, a child of
+the shell running the pipeline. A subprocess cannot affect its
+parent's environment. When the `read' command sets the variable
+to the input, that variable is set only in the subshell, not the
+parent shell. When the subshell exits, the value of the variable
+is lost.
+
+Many pipelines that end with `read variable' can be converted
+into command substitutions, which will capture the output of
+a specified command. The output can then be assigned to a
+variable:
+
+ grep ^gnu /usr/lib/news/active | wc -l | read ngroup
+
+can be converted into
+
+ ngroup=$(grep ^gnu /usr/lib/news/active | wc -l)
+
+This does not, unfortunately, work to split the text among
+multiple variables, as read does when given multiple variable
+arguments. If you need to do this, you can either use the
+command substitution above to read the output into a variable
+and chop up the variable using the bash pattern removal
+expansion operators or use some variant of the following
+approach.
+
+Say /usr/local/bin/ipaddr is the following shell script:
+
+#! /bin/sh
+host `hostname` | awk '/address/ {print $NF}'
+
+Instead of using
+
+ /usr/local/bin/ipaddr | read A B C D
+
+to break the local machine's IP address into separate octets, use
+
+ OIFS="$IFS"
+ IFS=.
+ set -- $(/usr/local/bin/ipaddr)
+ IFS="$OIFS"
+ A="$1" B="$2" C="$3" D="$4"
+
+Beware, however, that this will change the shell's positional
+parameters. If you need them, you should save them before doing
+this.
+
+This is the general approach -- in most cases you will not need to
+set $IFS to a different value.
+
+Some other user-supplied alternatives include:
+
+read A B C D << HERE
+ $(IFS=.; echo $(/usr/local/bin/ipaddr))
+HERE
+
+and, where process substitution is available,
+
+read A B C D < <(IFS=.; echo $(/usr/local/bin/ipaddr))
+
+E5) I have a bunch of shell scripts that use backslash-escaped characters
+ in arguments to `echo'. Bash doesn't interpret these characters. Why
+ not, and how can I make it understand them?
+
+This is the behavior of echo on most Unix System V machines.
+
+The bash builtin `echo' is modeled after the 9th Edition
+Research Unix version of `echo'. It does not interpret
+backslash-escaped characters in its argument strings by default;
+it requires the use of the -e option to enable the
+interpretation. The System V echo provides no way to disable the
+special characters; the bash echo has a -E option to disable
+them.
+
+There is a configuration option that will make bash behave like
+the System V echo and interpret things like `\t' by default. Run
+configure with the --enable-xpg-echo-default option to turn this
+on. Be aware that this will cause some of the tests run when you
+type `make tests' to fail.
+
+There is a shell option, `xpg_echo', settable with `shopt', that will
+change the behavior of echo at runtime. Enabling this option turns
+on expansion of backslash-escape sequences.
+
+E6) Why doesn't a while or for loop get suspended when I type ^Z?
+
+This is a consequence of how job control works on Unix. The only
+thing that can be suspended is the process group. This is a single
+command or pipeline of commands that the shell forks and executes.
+
+When you run a while or for loop, the only thing that the shell forks
+and executes are any commands in the while loop test and commands in
+the loop bodies. These, therefore, are the only things that can be
+suspended when you type ^Z.
+
+If you want to be able to stop the entire loop, you need to put it
+within parentheses, which will force the loop into a subshell that
+may be stopped (and subsequently restarted) as a single unit.
+
+E7) What about empty for loops in Makefiles?
+
+It's fairly common to see constructs like this in automatically-generated
+Makefiles:
+
+SUBDIRS = @SUBDIRS@
+
+ ...
+
+subdirs-clean:
+ for d in ${SUBDIRS}; do \
+ ( cd $$d && ${MAKE} ${MFLAGS} clean ) \
+ done
+
+When SUBDIRS is empty, this results in a command like this being passed to
+bash:
+
+ for d in ; do
+ ( cd $d && ${MAKE} ${MFLAGS} clean )
+ done
+
+In versions of bash before bash-2.05a, this was a syntax error. If the
+reserved word `in' was present, a word must follow it before the semicolon
+or newline. The language in the manual page referring to the list of words
+being empty referred to the list after it is expanded. These versions of
+bash required that there be at least one word following the `in' when the
+construct was parsed.
+
+The idiomatic Makefile solution is something like:
+
+SUBDIRS = @SUBDIRS@
+
+subdirs-clean:
+ subdirs=$SUBDIRS ; for d in $$subdirs; do \
+ ( cd $$d && ${MAKE} ${MFLAGS} clean ) \
+ done
+
+The latest drafts of the updated POSIX standard have changed this: the
+word list is no longer required. Bash versions 2.05a and later accept
+the new syntax.
+
+E8) Why does the arithmetic evaluation code complain about `08'?
+
+The bash arithmetic evaluation code (used for `let', $(()), (()), and in
+other places), interprets a leading `0' in numeric constants as denoting
+an octal number, and a leading `0x' as denoting hexadecimal. This is
+in accordance with the POSIX.2 spec, section 2.9.2.1, which states that
+arithmetic constants should be handled as signed long integers as defined
+by the ANSI/ISO C standard.
+
+The POSIX.2 interpretation committee has confirmed this:
+
+http://www.pasc.org/interps/unofficial/db/p1003.2/pasc-1003.2-173.html
+
+E9) Why does the pattern matching expression [A-Z]* match files beginning
+ with every letter except `z'?
+
+Bash-2.03, Bash-2.05 and later versions honor the current locale setting
+when processing ranges within pattern matching bracket expressions ([A-Z]).
+This is what POSIX.2 and SUSv3/XPG6 specify.
+
+The behavior of the matcher in bash-2.05 and later versions depends on the
+current LC_COLLATE setting. Setting this variable to `C' or `POSIX' will
+result in the traditional behavior ([A-Z] matches all uppercase ASCII
+characters). Many other locales, including the en_US locale (the default
+on many US versions of Linux) collate the upper and lower case letters like
+this:
+
+ AaBb...Zz
+
+which means that [A-Z] matches every letter except `z'. Others collate like
+
+ aAbBcC...zZ
+
+which means that [A-Z] matches every letter except `a'.
+
+The portable way to specify upper case letters is [:upper:] instead of
+A-Z; lower case may be specified as [:lower:] instead of a-z.
+
+Look at the manual pages for setlocale(3), strcoll(3), and, if it is
+present, locale(1). If you have locale(1), you can use it to find
+your current locale information even if you do not have any of the
+LC_ variables set.
+
+My advice is to put
+
+ export LC_COLLATE=C
+
+into /etc/profile and inspect any shell scripts run from cron for
+constructs like [A-Z]. This will prevent things like
+
+ rm [A-Z]*
+
+from removing every file in the current directory except those beginning
+with `z' and still allow individual users to change the collation order.
+Users may put the above command into their own profiles as well, of course.
+
+E10) Why does `cd //' leave $PWD as `//'?
+
+POSIX.2, in its description of `cd', says that *three* or more leading
+slashes may be replaced with a single slash when canonicalizing the
+current working directory.
+
+This is, I presume, for historical compatibility. Certain versions of
+Unix, and early network file systems, used paths of the form
+//hostname/path to access `path' on server `hostname'.
+
+E11) If I resize my xterm while another program is running, why doesn't bash
+ notice the change?
+
+This is another issue that deals with job control.
+
+The kernel maintains a notion of a current terminal process group. Members
+of this process group (processes whose process group ID is equal to the
+current terminal process group ID) receive terminal-generated signals like
+SIGWINCH. (For more details, see the JOB CONTROL section of the bash
+man page.)
+
+If a terminal is resized, the kernel sends SIGWINCH to each member of
+the terminal's current process group (the `foreground' process group).
+
+When bash is running with job control enabled, each pipeline (which may be
+a single command) is run in its own process group, different from bash's
+process group. This foreground process group receives the SIGWINCH; bash
+does not. Bash has no way of knowing that the terminal has been resized.
+
+There is a `checkwinsize' option, settable with the `shopt' builtin, that
+will cause bash to check the window size and adjust its idea of the
+terminal's dimensions each time a process stops or exits and returns control
+of the terminal to bash. Enable it with `shopt -s checkwinsize'.
+
+Section F: Things to watch out for on certain Unix versions
+
+F1) Why can't I use command line editing in my `cmdtool'?
+
+The problem is `cmdtool' and bash fighting over the input. When
+scrolling is enabled in a cmdtool window, cmdtool puts the tty in
+`raw mode' to permit command-line editing using the mouse for
+applications that cannot do it themselves. As a result, bash and
+cmdtool each try to read keyboard input immediately, with neither
+getting enough of it to be useful.
+
+This mode also causes cmdtool to not implement many of the
+terminal functions and control sequences appearing in the
+`sun-cmd' termcap entry. For a more complete explanation, see
+that file examples/suncmd.termcap in the bash distribution.
+
+`xterm' is a better choice, and gets along with bash much more
+smoothly.
+
+If you must use cmdtool, you can use the termcap description in
+examples/suncmd.termcap. Set the TERMCAP variable to the terminal
+description contained in that file, i.e.
+
+TERMCAP='Mu|sun-cmd:am:bs:km:pt:li#34:co#80:cl=^L:ce=\E[K:cd=\E[J:rs=\E[s:'
+
+Then export TERMCAP and start a new cmdtool window from that shell.
+The bash command-line editing should behave better in the new
+cmdtool. If this works, you can put the assignment to TERMCAP
+in your bashrc file.
+
+F2) I built bash on Solaris 2. Why do globbing expansions and filename
+ completion chop off the first few characters of each filename?
+
+This is the consequence of building bash on SunOS 5 and linking
+with the libraries in /usr/ucblib, but using the definitions
+and structures from files in /usr/include.
+
+The actual conflict is between the dirent structure in
+/usr/include/dirent.h and the struct returned by the version of
+`readdir' in libucb.a (a 4.3-BSD style `struct direct').
+
+Make sure you've got /usr/ccs/bin ahead of /usr/ucb in your $PATH
+when configuring and building bash. This will ensure that you
+use /usr/ccs/bin/cc or acc instead of /usr/ucb/cc and that you
+link with libc before libucb.
+
+If you have installed the Sun C compiler, you may also need to
+put /usr/ccs/bin and /opt/SUNWspro/bin into your $PATH before
+/usr/ucb.
+
+F3) Why does bash dump core after I interrupt username completion or
+ `~user' tilde expansion on a machine running NIS?
+
+This is a famous and long-standing bug in the SunOS YP (sorry, NIS)
+client library, which is part of libc.
+
+The YP library code keeps static state -- a pointer into the data
+returned from the server. When YP initializes itself (setpwent),
+it looks at this pointer and calls free on it if it's non-null.
+So far, so good.
+
+If one of the YP functions is interrupted during getpwent (the
+exact function is interpretwithsave()), and returns NULL, the
+pointer is freed without being reset to NULL, and the function
+returns. The next time getpwent is called, it sees that this
+pointer is non-null, calls free, and the bash free() blows up
+because it's being asked to free freed memory.
+
+The traditional Unix mallocs allow memory to be freed multiple
+times; that's probably why this has never been fixed. You can
+run configure with the `--without-gnu-malloc' option to use
+the C library malloc and avoid the problem.
+
+F4) I'm running SVR4.2. Why is the line erased every time I type `@'?
+
+The `@' character is the default `line kill' character in most
+versions of System V, including SVR4.2. You can change this
+character to whatever you want using `stty'. For example, to
+change the line kill character to control-u, type
+
+ stty kill ^U
+
+where the `^' and `U' can be two separate characters.
+
+F5) Why does bash report syntax errors when my C News scripts use a
+ redirection before a subshell command?
+
+The actual command in question is something like
+
+ < file ( command )
+
+According to the grammar given in the POSIX.2 standard, this construct
+is, in fact, a syntax error. Redirections may only precede `simple
+commands'. A subshell construct such as the above is one of the shell's
+`compound commands'. A redirection may only follow a compound command.
+
+This affects the mechanical transformation of commands that use `cat'
+to pipe a file into a command (a favorite Useless-Use-Of-Cat topic on
+comp.unix.shell). While most commands of the form
+
+ cat file | command
+
+can be converted to `< file command', shell control structures such as
+loops and subshells require `command < file'.
+
+The file CWRU/sh-redir-hack in the bash-2.05a distribution is an
+(unofficial) patch to parse.y that will modify the grammar to
+support this construct. It will not apply with `patch'; you must
+modify parse.y by hand. Note that if you apply this, you must
+recompile with -DREDIRECTION_HACK. This introduces a large
+number of reduce/reduce conflicts into the shell grammar.
+
+F6) Why can't I use vi-mode editing on Red Hat Linux 6.1?
+
+The short answer is that Red Hat screwed up.
+
+The long answer is that they shipped an /etc/inputrc that only works
+for emacs mode editing, and then screwed all the vi users by setting
+INPUTRC to /etc/inputrc in /etc/profile.
+
+The short fix is to do one of the following: remove or rename
+/etc/inputrc, set INPUTRC=~/.inputrc in ~/.bashrc (or .bash_profile,
+but make sure you export it if you do), remove the assignment to
+INPUTRC from /etc/profile, add
+
+ set keymap emacs
+
+to the beginning of /etc/inputrc, or bracket the key bindings in
+/etc/inputrc with these lines
+
+ $if mode=emacs
+ [...]
+ $endif
+
+F7) Why do bash-2.05a and bash-2.05b fail to compile `printf.def' on
+ HP/UX 11.x?
+
+HP/UX's support for long double is imperfect at best.
+
+GCC will support it without problems, but the HP C library functions
+like strtold(3) and printf(3) don't actually work with long doubles.
+HP implemented a `long_double' type as a 4-element array of 32-bit
+ints, and that is what the library functions use. The ANSI C
+`long double' type is a 128-bit floating point scalar.
+
+The easiest fix, until HP fixes things up, is to edit the generated
+config.h and #undef the HAVE_LONG_DOUBLE line. After doing that,
+the compilation should complete successfully.
+
+Section G: How can I get bash to do certain common things?
+
+G1) How can I get bash to read and display eight-bit characters?
+
+This is a process requiring several steps.
+
+First, you must ensure that the `physical' data path is a full eight
+bits. For xterms, for example, the `vt100' resources `eightBitInput'
+and `eightBitOutput' should be set to `true'.
+
+Once you have set up an eight-bit path, you must tell the kernel and
+tty driver to leave the eighth bit of characters alone when processing
+keyboard input. Use `stty' to do this:
+
+ stty cs8 -istrip -parenb
+
+For old BSD-style systems, you can use
+
+ stty pass8
+
+You may also need
+
+ stty even odd
+
+Finally, you need to tell readline that you will be inputting and
+displaying eight-bit characters. You use readline variables to do
+this. These variables can be set in your .inputrc or using the bash
+`bind' builtin. Here's an example using `bind':
+
+ bash$ bind 'set convert-meta off'
+ bash$ bind 'set meta-flag on'
+ bash$ bind 'set output-meta on'
+
+The `set' commands between the single quotes may also be placed
+in ~/.inputrc.
+
+G2) How do I write a function `x' to replace builtin command `x', but
+ still invoke the command from within the function?
+
+This is why the `command' and `builtin' builtins exist. The
+`command' builtin executes the command supplied as its first
+argument, skipping over any function defined with that name. The
+`builtin' builtin executes the builtin command given as its first
+argument directly.
+
+For example, to write a function to replace `cd' that writes the
+hostname and current directory to an xterm title bar, use
+something like the following:
+
+ cd()
+ {
+ builtin cd "$@" && xtitle "$HOST: $PWD"
+ }
+
+This could also be written using `command' instead of `builtin';
+the version above is marginally more efficient.
+
+G3) How can I find the value of a shell variable whose name is the value
+ of another shell variable?
+
+Versions of Bash newer than Bash-2.0 support this directly. You can use
+
+ ${!var}
+
+For example, the following sequence of commands will echo `z':
+
+ var1=var2
+ var2=z
+ echo ${!var1}
+
+For sh compatibility, use the `eval' builtin. The important
+thing to remember is that `eval' expands the arguments you give
+it again, so you need to quote the parts of the arguments that
+you want `eval' to act on.
+
+For example, this expression prints the value of the last positional
+parameter:
+
+ eval echo \"\$\{$#\}\"
+
+The expansion of the quoted portions of this expression will be
+deferred until `eval' runs, while the `$#' will be expanded
+before `eval' is executed. In versions of bash later than bash-2.0,
+
+ echo ${!#}
+
+does the same thing.
+
+This is not the same thing as ksh93 `nameref' variables, though the syntax
+is similar. I may add namerefs in a future bash version.
+
+G4) How can I make the bash `time' reserved word print timing output that
+ looks like the output from my system's /usr/bin/time?
+
+The bash command timing code looks for a variable `TIMEFORMAT' and
+uses its value as a format string to decide how to display the
+timing statistics.
+
+The value of TIMEFORMAT is a string with `%' escapes expanded in a
+fashion similar in spirit to printf(3). The manual page explains
+the meanings of the escape sequences in the format string.
+
+If TIMEFORMAT is not set, bash acts as if the following assignment had
+been performed:
+
+ TIMEFORMAT=$'\nreal\t%3lR\nuser\t%3lU\nsys\t%3lS'
+
+The POSIX.2 default time format (used by `time -p command') is
+
+ TIMEFORMAT=$'real %2R\nuser %2U\nsys %2S'
+
+The BSD /usr/bin/time format can be emulated with:
+
+ TIMEFORMAT=$'\t%1R real\t%1U user\t%1S sys'
+
+The System V /usr/bin/time format can be emulated with:
+
+ TIMEFORMAT=$'\nreal\t%1R\nuser\t%1U\nsys\t%1S'
+
+The ksh format can be emulated with:
+
+ TIMEFORMAT=$'\nreal\t%2lR\nuser\t%2lU\nsys\t%2lS'
+
+G5) How do I get the current directory into my prompt?
+
+Bash provides a number of backslash-escape sequences which are expanded
+when the prompt string (PS1 or PS2) is displayed. The full list is in
+the manual page.
+
+The \w expansion gives the full pathname of the current directory, with
+a tilde (`~') substituted for the current value of $HOME. The \W
+expansion gives the basename of the current directory. To put the full
+pathname of the current directory into the path without any tilde
+subsitution, use $PWD. Here are some examples:
+
+ PS1='\w$ ' # current directory with tilde
+ PS1='\W$ ' # basename of current directory
+ PS1='$PWD$ ' # full pathname of current directory
+
+The single quotes are important in the final example to prevent $PWD from
+being expanded when the assignment to PS1 is performed.
+
+G6) How can I rename "*.foo" to "*.bar"?
+
+Use the pattern removal functionality described in D3. The following `for'
+loop will do the trick:
+
+ for f in *.foo; do
+ mv $f ${f%foo}bar
+ done
+
+G7) How can I translate a filename from uppercase to lowercase?
+
+The script examples/functions/lowercase, originally written by John DuBois,
+will do the trick. The converse is left as an exercise.
+
+G8) How can I write a filename expansion (globbing) pattern that will match
+ all files in the current directory except "." and ".."?
+
+You must have set the `extglob' shell option using `shopt -s extglob' to use
+this:
+
+ echo .!(.|) *
+
+A solution that works without extended globbing is given in the Unix Shell
+FAQ, posted periodically to comp.unix.shell.
+
+Section H: Where do I go from here?
+
+H1) How do I report bugs in bash, and where should I look for fixes and
+ advice?
+
+Use the `bashbug' script to report bugs. It is built and
+installed at the same time as bash. It provides a standard
+template for reporting a problem and automatically includes
+information about your configuration and build environment.
+
+`bashbug' sends its reports to bug-bash@gnu.org, which
+is a large mailing list gatewayed to the usenet newsgroup gnu.bash.bug.
+
+Bug fixes, answers to questions, and announcements of new releases
+are all posted to gnu.bash.bug. Discussions concerning bash features
+and problems also take place there.
+
+To reach the bash maintainers directly, send mail to
+bash-maintainers@gnu.org.
+
+H2) What kind of bash documentation is there?
+
+First, look in the doc directory in the bash distribution. It should
+contain at least the following files:
+
+bash.1 an extensive, thorough Unix-style manual page
+builtins.1 a manual page covering just bash builtin commands
+bashref.texi a reference manual in GNU tex`info format
+bashref.info an info version of the reference manual
+FAQ this file
+article.ms text of an article written for The Linux Journal
+readline.3 a man page describing readline
+
+Postscript, HTML, and ASCII files created from the above source are
+available in the documentation distribution.
+
+There is additional documentation available for anonymous FTP from host
+ftp.cwru.edu in the `pub/bash' directory.
+
+Cameron Newham and Bill Rosenblatt have written a book on bash, published
+by O'Reilly and Associates. The book is based on Bill Rosenblatt's Korn
+Shell book. The title is ``Learning the Bash Shell'', and the ISBN number
+is 1-56592-147-X. Look for it in fine bookstores near you. This book
+covers bash-1.14, but has an appendix describing some of the new features
+in bash-2.0.
+
+A second edition of this book is available, published in January, 1998.
+The ISBN number is 1-56592-347-2. Look for it in the same fine bookstores
+or on the web.
+
+The GNU Bash Reference Manual has been published as a printed book by
+Network Theory Ltd (Paperback, ISBN: 0-9541617-7-7, Feb 2003). It covers
+bash-2.0 and is available from most online bookstores (see
+http://www.network-theory.co.uk/bash/manual/ for details). The publisher
+will donate $1 to the Free Software Foundation for each copy sold.
+
+H3) What's coming in future versions?
+
+These are features I hope to include in a future version of bash.
+
+a better bash debugger (a minimally-tested version is included with bash-2.05b)
+associative arrays
+co-processes, but with a new-style syntax that looks like function declaration
+
+H4) What's on the bash `wish list' for future versions?
+
+These are features that may or may not appear in a future version of bash.
+
+breaking some of the shell functionality into embeddable libraries
+a module system like zsh's, using dynamic loading like builtins
+better internationalization using GNU `gettext'
+date-stamped command history
+a bash programmer's guide with a chapter on creating loadable builtins
+a better loadable interface to perl with access to the shell builtins and
+ variables (contributions gratefully accepted)
+ksh93-like `nameref' variables
+ksh93-like `+=' variable assignment operator
+ksh93-like `xx.yy' variables (including some of the .sh.* variables) and
+ associated disipline functions
+Some of the new ksh93 pattern matching operators, like backreferencing
+
+H5) When will the next release appear?
+
+The next version will appear sometime in 2002. Never make predictions.
+
+
+This document is Copyright 1995-2003 by Chester Ramey.
+
+Permission is hereby granted, without written agreement and
+without license or royalty fees, to use, copy, and distribute
+this document for any purpose, provided that the above copyright
+notice appears in all copies of this document and that the
+contents of this document remain unaltered.
--- /dev/null
+/* variables.c -- Functions for hacking shell variables. */
+
+/* Copyright (C) 1987-2013 Free Software Foundation, Inc.
+
+ This file is part of GNU Bash, the Bourne Again SHell.
+
+ Bash is free software: you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation, either version 3 of the License, or
+ (at your option) any later version.
+
+ Bash is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with Bash. If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include "config.h"
+
+#include "bashtypes.h"
+#include "posixstat.h"
+#include "posixtime.h"
+
+#if defined (__QNX__)
+# if defined (__QNXNTO__)
+# include <sys/netmgr.h>
+# else
+# include <sys/vc.h>
+# endif /* !__QNXNTO__ */
+#endif /* __QNX__ */
+
+#if defined (HAVE_UNISTD_H)
+# include <unistd.h>
+#endif
+
+#include <stdio.h>
+#include "chartypes.h"
+#if defined (HAVE_PWD_H)
+# include <pwd.h>
+#endif
+#include "bashansi.h"
+#include "bashintl.h"
+
+#define NEED_XTRACE_SET_DECL
+
+#include "shell.h"
+#include "flags.h"
+#include "execute_cmd.h"
+#include "findcmd.h"
+#include "mailcheck.h"
+#include "input.h"
+#include "hashcmd.h"
+#include "pathexp.h"
+#include "alias.h"
+#include "jobs.h"
+
+#include "version.h"
+
+#include "builtins/getopt.h"
+#include "builtins/common.h"
+#include "builtins/builtext.h"
+
+#if defined (READLINE)
+# include "bashline.h"
+# include <readline/readline.h>
+#else
+# include <tilde/tilde.h>
+#endif
+
+#if defined (HISTORY)
+# include "bashhist.h"
+# include <readline/history.h>
+#endif /* HISTORY */
+
+#if defined (PROGRAMMABLE_COMPLETION)
+# include "pcomplete.h"
+#endif
+
+#define TEMPENV_HASH_BUCKETS 4 /* must be power of two */
+
+#define ifsname(s) ((s)[0] == 'I' && (s)[1] == 'F' && (s)[2] == 'S' && (s)[3] == '\0')
+
+/* flags for find_variable_internal */
+
+#define FV_FORCETEMPENV 0x01
+#define FV_SKIPINVISIBLE 0x02
+
+extern char **environ;
+
+/* Variables used here and defined in other files. */
+extern int posixly_correct;
+extern int line_number, line_number_base;
+extern int subshell_environment, indirection_level, subshell_level;
+extern int build_version, patch_level;
+extern int expanding_redir;
+extern int last_command_exit_value;
+extern char *dist_version, *release_status;
+extern char *shell_name;
+extern char *primary_prompt, *secondary_prompt;
+extern char *current_host_name;
+extern sh_builtin_func_t *this_shell_builtin;
+extern SHELL_VAR *this_shell_function;
+extern char *the_printed_command_except_trap;
+extern char *this_command_name;
+extern char *command_execution_string;
+extern time_t shell_start_time;
+extern int assigning_in_environment;
+extern int executing_builtin;
+extern int funcnest_max;
+
+#if defined (READLINE)
+extern int no_line_editing;
+extern int perform_hostname_completion;
+#endif
+
+/* The list of shell variables that the user has created at the global
+ scope, or that came from the environment. */
+VAR_CONTEXT *global_variables = (VAR_CONTEXT *)NULL;
+
+/* The current list of shell variables, including function scopes */
+VAR_CONTEXT *shell_variables = (VAR_CONTEXT *)NULL;
+
+/* The list of shell functions that the user has created, or that came from
+ the environment. */
+HASH_TABLE *shell_functions = (HASH_TABLE *)NULL;
+
+#if defined (DEBUGGER)
+/* The table of shell function definitions that the user defined or that
+ came from the environment. */
+HASH_TABLE *shell_function_defs = (HASH_TABLE *)NULL;
+#endif
+
+/* The current variable context. This is really a count of how deep into
+ executing functions we are. */
+int variable_context = 0;
+
+/* The set of shell assignments which are made only in the environment
+ for a single command. */
+HASH_TABLE *temporary_env = (HASH_TABLE *)NULL;
+
+/* Set to non-zero if an assignment error occurs while putting variables
+ into the temporary environment. */
+int tempenv_assign_error;
+
+/* Some funky variables which are known about specially. Here is where
+ "$*", "$1", and all the cruft is kept. */
+char *dollar_vars[10];
+WORD_LIST *rest_of_args = (WORD_LIST *)NULL;
+
+/* The value of $$. */
+pid_t dollar_dollar_pid;
+
+/* Non-zero means that we have to remake EXPORT_ENV. */
+int array_needs_making = 1;
+
+/* The number of times BASH has been executed. This is set
+ by initialize_variables (). */
+int shell_level = 0;
+
+/* An array which is passed to commands as their environment. It is
+ manufactured from the union of the initial environment and the
+ shell variables that are marked for export. */
+char **export_env = (char **)NULL;
+static int export_env_index;
+static int export_env_size;
+
+#if defined (READLINE)
+static int winsize_assignment; /* currently assigning to LINES or COLUMNS */
+#endif
+
+static HASH_TABLE *last_table_searched; /* hash_lookup sets this */
+
+/* Some forward declarations. */
+static void create_variable_tables __P((void));
+
+static void set_machine_vars __P((void));
+static void set_home_var __P((void));
+static void set_shell_var __P((void));
+static char *get_bash_name __P((void));
+static void initialize_shell_level __P((void));
+static void uidset __P((void));
+#if defined (ARRAY_VARS)
+static void make_vers_array __P((void));
+#endif
+
+static SHELL_VAR *null_assign __P((SHELL_VAR *, char *, arrayind_t, char *));
+#if defined (ARRAY_VARS)
+static SHELL_VAR *null_array_assign __P((SHELL_VAR *, char *, arrayind_t, char *));
+#endif
+static SHELL_VAR *get_self __P((SHELL_VAR *));
+
+#if defined (ARRAY_VARS)
+static SHELL_VAR *init_dynamic_array_var __P((char *, sh_var_value_func_t *, sh_var_assign_func_t *, int));
+static SHELL_VAR *init_dynamic_assoc_var __P((char *, sh_var_value_func_t *, sh_var_assign_func_t *, int));
+#endif
+
+static SHELL_VAR *assign_seconds __P((SHELL_VAR *, char *, arrayind_t, char *));
+static SHELL_VAR *get_seconds __P((SHELL_VAR *));
+static SHELL_VAR *init_seconds_var __P((void));
+
+static int brand __P((void));
+static void sbrand __P((unsigned long)); /* set bash random number generator. */
+static void seedrand __P((void)); /* seed generator randomly */
+static SHELL_VAR *assign_random __P((SHELL_VAR *, char *, arrayind_t, char *));
+static SHELL_VAR *get_random __P((SHELL_VAR *));
+
+static SHELL_VAR *assign_lineno __P((SHELL_VAR *, char *, arrayind_t, char *));
+static SHELL_VAR *get_lineno __P((SHELL_VAR *));
+
+static SHELL_VAR *assign_subshell __P((SHELL_VAR *, char *, arrayind_t, char *));
+static SHELL_VAR *get_subshell __P((SHELL_VAR *));
+
+static SHELL_VAR *get_bashpid __P((SHELL_VAR *));
+
+#if defined (HISTORY)
+static SHELL_VAR *get_histcmd __P((SHELL_VAR *));
+#endif
+
+#if defined (READLINE)
+static SHELL_VAR *get_comp_wordbreaks __P((SHELL_VAR *));
+static SHELL_VAR *assign_comp_wordbreaks __P((SHELL_VAR *, char *, arrayind_t, char *));
+#endif
+
+#if defined (PUSHD_AND_POPD) && defined (ARRAY_VARS)
+static SHELL_VAR *assign_dirstack __P((SHELL_VAR *, char *, arrayind_t, char *));
+static SHELL_VAR *get_dirstack __P((SHELL_VAR *));
+#endif
+
+#if defined (ARRAY_VARS)
+static SHELL_VAR *get_groupset __P((SHELL_VAR *));
+
+static SHELL_VAR *build_hashcmd __P((SHELL_VAR *));
+static SHELL_VAR *get_hashcmd __P((SHELL_VAR *));
+static SHELL_VAR *assign_hashcmd __P((SHELL_VAR *, char *, arrayind_t, char *));
+# if defined (ALIAS)
+static SHELL_VAR *build_aliasvar __P((SHELL_VAR *));
+static SHELL_VAR *get_aliasvar __P((SHELL_VAR *));
+static SHELL_VAR *assign_aliasvar __P((SHELL_VAR *, char *, arrayind_t, char *));
+# endif
+#endif
+
+static SHELL_VAR *get_funcname __P((SHELL_VAR *));
+static SHELL_VAR *init_funcname_var __P((void));
+
+static void initialize_dynamic_variables __P((void));
+
+static SHELL_VAR *hash_lookup __P((const char *, HASH_TABLE *));
+static SHELL_VAR *new_shell_variable __P((const char *));
+static SHELL_VAR *make_new_variable __P((const char *, HASH_TABLE *));
+static SHELL_VAR *bind_variable_internal __P((const char *, char *, HASH_TABLE *, int, int));
+
+static void dispose_variable_value __P((SHELL_VAR *));
+static void free_variable_hash_data __P((PTR_T));
+
+static VARLIST *vlist_alloc __P((int));
+static VARLIST *vlist_realloc __P((VARLIST *, int));
+static void vlist_add __P((VARLIST *, SHELL_VAR *, int));
+
+static void flatten __P((HASH_TABLE *, sh_var_map_func_t *, VARLIST *, int));
+
+static int qsort_var_comp __P((SHELL_VAR **, SHELL_VAR **));
+
+static SHELL_VAR **vapply __P((sh_var_map_func_t *));
+static SHELL_VAR **fapply __P((sh_var_map_func_t *));
+
+static int visible_var __P((SHELL_VAR *));
+static int visible_and_exported __P((SHELL_VAR *));
+static int export_environment_candidate __P((SHELL_VAR *));
+static int local_and_exported __P((SHELL_VAR *));
+static int variable_in_context __P((SHELL_VAR *));
+#if defined (ARRAY_VARS)
+static int visible_array_vars __P((SHELL_VAR *));
+#endif
+
+static SHELL_VAR *find_nameref_at_context __P((SHELL_VAR *, VAR_CONTEXT *));
+static SHELL_VAR *find_variable_nameref_context __P((SHELL_VAR *, VAR_CONTEXT *, VAR_CONTEXT **));
+static SHELL_VAR *find_variable_last_nameref_context __P((SHELL_VAR *, VAR_CONTEXT *, VAR_CONTEXT **));
+
+static SHELL_VAR *bind_tempenv_variable __P((const char *, char *));
+static void push_temp_var __P((PTR_T));
+static void propagate_temp_var __P((PTR_T));
+static void dispose_temporary_env __P((sh_free_func_t *));
+
+static inline char *mk_env_string __P((const char *, const char *));
+static char **make_env_array_from_var_list __P((SHELL_VAR **));
+static char **make_var_export_array __P((VAR_CONTEXT *));
+static char **make_func_export_array __P((void));
+static void add_temp_array_to_env __P((char **, int, int));
+
+static int n_shell_variables __P((void));
+static int set_context __P((SHELL_VAR *));
+
+static void push_func_var __P((PTR_T));
+static void push_exported_var __P((PTR_T));
+
+static inline int find_special_var __P((const char *));
+
+static void
+create_variable_tables ()
+{
+ if (shell_variables == 0)
+ {
+ shell_variables = global_variables = new_var_context ((char *)NULL, 0);
+ shell_variables->scope = 0;
+ shell_variables->table = hash_create (0);
+ }
+
+ if (shell_functions == 0)
+ shell_functions = hash_create (0);
+
+#if defined (DEBUGGER)
+ if (shell_function_defs == 0)
+ shell_function_defs = hash_create (0);
+#endif
+}
+
+/* Initialize the shell variables from the current environment.
+ If PRIVMODE is nonzero, don't import functions from ENV or
+ parse $SHELLOPTS. */
+void
+initialize_shell_variables (env, privmode)
+ char **env;
+ int privmode;
+{
+ char *name, *string, *temp_string;
+ int c, char_index, string_index, string_length, ro;
+ SHELL_VAR *temp_var;
+
+ create_variable_tables ();
+
+ for (string_index = 0; string = env[string_index++]; )
+ {
+ char_index = 0;
+ name = string;
+ while ((c = *string++) && c != '=')
+ ;
+ if (string[-1] == '=')
+ char_index = string - name - 1;
+
+ /* If there are weird things in the environment, like `=xxx' or a
+ string without an `=', just skip them. */
+ if (char_index == 0)
+ continue;
+
+ /* ASSERT(name[char_index] == '=') */
+ name[char_index] = '\0';
+ /* Now, name = env variable name, string = env variable value, and
+ char_index == strlen (name) */
+
+ temp_var = (SHELL_VAR *)NULL;
+
+ /* If exported function, define it now. Don't import functions from
+ the environment in privileged mode. */
+ if (privmode == 0 && read_but_dont_execute == 0 && STREQN ("() {", string, 4))
+ {
+ string_length = strlen (string);
+ temp_string = (char *)xmalloc (3 + string_length + char_index);
+
+ strcpy (temp_string, name);
+ temp_string[char_index] = ' ';
+ strcpy (temp_string + char_index + 1, string);
+
+ if (posixly_correct == 0 || legal_identifier (name))
+ parse_and_execute (temp_string, name, SEVAL_NONINT|SEVAL_NOHIST);
+
+ /* Ancient backwards compatibility. Old versions of bash exported
+ functions like name()=() {...} */
+ if (name[char_index - 1] == ')' && name[char_index - 2] == '(')
+ name[char_index - 2] = '\0';
+
+ if (temp_var = find_function (name))
+ {
+ VSETATTR (temp_var, (att_exported|att_imported));
+ array_needs_making = 1;
+ }
+ else
+ {
+ if (temp_var = bind_variable (name, string, 0))
+ {
+ VSETATTR (temp_var, (att_exported | att_imported | att_invisible));
+ array_needs_making = 1;
+ }
+ last_command_exit_value = 1;
+ report_error (_("error importing function definition for `%s'"), name);
+ }
+
+ /* ( */
+ if (name[char_index - 1] == ')' && name[char_index - 2] == '\0')
+ name[char_index - 2] = '('; /* ) */
+ }
+#if defined (ARRAY_VARS)
+# if ARRAY_EXPORT
+ /* Array variables may not yet be exported. */
+ else if (*string == '(' && string[1] == '[' && string[strlen (string) - 1] == ')')
+ {
+ string_length = 1;
+ temp_string = extract_array_assignment_list (string, &string_length);
+ temp_var = assign_array_from_string (name, temp_string);
+ FREE (temp_string);
+ VSETATTR (temp_var, (att_exported | att_imported));
+ array_needs_making = 1;
+ }
+# endif /* ARRAY_EXPORT */
+#endif
+#if 0
+ else if (legal_identifier (name))
+#else
+ else
+#endif
+ {
+ ro = 0;
+ if (posixly_correct && STREQ (name, "SHELLOPTS"))
+ {
+ temp_var = find_variable ("SHELLOPTS");
+ ro = temp_var && readonly_p (temp_var);
+ if (temp_var)
+ VUNSETATTR (temp_var, att_readonly);
+ }
+ temp_var = bind_variable (name, string, 0);
+ if (temp_var)
+ {
+ if (legal_identifier (name))
+ VSETATTR (temp_var, (att_exported | att_imported));
+ else
+ VSETATTR (temp_var, (att_exported | att_imported | att_invisible));
+ if (ro)
+ VSETATTR (temp_var, att_readonly);
+ array_needs_making = 1;
+ }
+ }
+
+ name[char_index] = '=';
+ /* temp_var can be NULL if it was an exported function with a syntax
+ error (a different bug, but it still shouldn't dump core). */
+ if (temp_var && function_p (temp_var) == 0) /* XXX not yet */
+ {
+ CACHE_IMPORTSTR (temp_var, name);
+ }
+ }
+
+ set_pwd ();
+
+ /* Set up initial value of $_ */
+ temp_var = set_if_not ("_", dollar_vars[0]);
+
+ /* Remember this pid. */
+ dollar_dollar_pid = getpid ();
+
+ /* Now make our own defaults in case the vars that we think are
+ important are missing. */
+ temp_var = set_if_not ("PATH", DEFAULT_PATH_VALUE);
+#if 0
+ set_auto_export (temp_var); /* XXX */
+#endif
+
+ temp_var = set_if_not ("TERM", "dumb");
+#if 0
+ set_auto_export (temp_var); /* XXX */
+#endif
+
+#if defined (__QNX__)
+ /* set node id -- don't import it from the environment */
+ {
+ char node_name[22];
+# if defined (__QNXNTO__)
+ netmgr_ndtostr(ND2S_LOCAL_STR, ND_LOCAL_NODE, node_name, sizeof(node_name));
+# else
+ qnx_nidtostr (getnid (), node_name, sizeof (node_name));
+# endif
+ temp_var = bind_variable ("NODE", node_name, 0);
+ set_auto_export (temp_var);
+ }
+#endif
+
+ /* set up the prompts. */
+ if (interactive_shell)
+ {
+#if defined (PROMPT_STRING_DECODE)
+ set_if_not ("PS1", primary_prompt);
+#else
+ if (current_user.uid == -1)
+ get_current_user_info ();
+ set_if_not ("PS1", current_user.euid == 0 ? "# " : primary_prompt);
+#endif
+ set_if_not ("PS2", secondary_prompt);
+ }
+ set_if_not ("PS4", "+ ");
+
+ /* Don't allow IFS to be imported from the environment. */
+ temp_var = bind_variable ("IFS", " \t\n", 0);
+ setifs (temp_var);
+
+ /* Magic machine types. Pretty convenient. */
+ set_machine_vars ();
+
+ /* Default MAILCHECK for interactive shells. Defer the creation of a
+ default MAILPATH until the startup files are read, because MAIL
+ names a mail file if MAILPATH is not set, and we should provide a
+ default only if neither is set. */
+ if (interactive_shell)
+ {
+ temp_var = set_if_not ("MAILCHECK", posixly_correct ? "600" : "60");
+ VSETATTR (temp_var, att_integer);
+ }
+
+ /* Do some things with shell level. */
+ initialize_shell_level ();
+
+ set_ppid ();
+
+ /* Initialize the `getopts' stuff. */
+ temp_var = bind_variable ("OPTIND", "1", 0);
+ VSETATTR (temp_var, att_integer);
+ getopts_reset (0);
+ bind_variable ("OPTERR", "1", 0);
+ sh_opterr = 1;
+
+ if (login_shell == 1 && posixly_correct == 0)
+ set_home_var ();
+
+ /* Get the full pathname to THIS shell, and set the BASH variable
+ to it. */
+ name = get_bash_name ();
+ temp_var = bind_variable ("BASH", name, 0);
+ free (name);
+
+ /* Make the exported environment variable SHELL be the user's login
+ shell. Note that the `tset' command looks at this variable
+ to determine what style of commands to output; if it ends in "csh",
+ then C-shell commands are output, else Bourne shell commands. */
+ set_shell_var ();
+
+ /* Make a variable called BASH_VERSION which contains the version info. */
+ bind_variable ("BASH_VERSION", shell_version_string (), 0);
+#if defined (ARRAY_VARS)
+ make_vers_array ();
+#endif
+
+ if (command_execution_string)
+ bind_variable ("BASH_EXECUTION_STRING", command_execution_string, 0);
+
+ /* Find out if we're supposed to be in Posix.2 mode via an
+ environment variable. */
+ temp_var = find_variable ("POSIXLY_CORRECT");
+ if (!temp_var)
+ temp_var = find_variable ("POSIX_PEDANTIC");
+ if (temp_var && imported_p (temp_var))
+ sv_strict_posix (temp_var->name);
+
+#if defined (HISTORY)
+ /* Set history variables to defaults, and then do whatever we would
+ do if the variable had just been set. Do this only in the case
+ that we are remembering commands on the history list. */
+ if (remember_on_history)
+ {
+ name = bash_tilde_expand (posixly_correct ? "~/.sh_history" : "~/.bash_history", 0);
+
+ set_if_not ("HISTFILE", name);
+ free (name);
+ }
+#endif /* HISTORY */
+
+ /* Seed the random number generator. */
+ seedrand ();
+
+ /* Handle some "special" variables that we may have inherited from a
+ parent shell. */
+ if (interactive_shell)
+ {
+ temp_var = find_variable ("IGNOREEOF");
+ if (!temp_var)
+ temp_var = find_variable ("ignoreeof");
+ if (temp_var && imported_p (temp_var))
+ sv_ignoreeof (temp_var->name);
+ }
+
+#if defined (HISTORY)
+ if (interactive_shell && remember_on_history)
+ {
+ sv_history_control ("HISTCONTROL");
+ sv_histignore ("HISTIGNORE");
+ sv_histtimefmt ("HISTTIMEFORMAT");
+ }
+#endif /* HISTORY */
+
+#if defined (READLINE) && defined (STRICT_POSIX)
+ /* POSIXLY_CORRECT will only be 1 here if the shell was compiled
+ -DSTRICT_POSIX */
+ if (interactive_shell && posixly_correct && no_line_editing == 0)
+ rl_prefer_env_winsize = 1;
+#endif /* READLINE && STRICT_POSIX */
+
+ /*
+ * 24 October 2001
+ *
+ * I'm tired of the arguing and bug reports. Bash now leaves SSH_CLIENT
+ * and SSH2_CLIENT alone. I'm going to rely on the shell_level check in
+ * isnetconn() to avoid running the startup files more often than wanted.
+ * That will, of course, only work if the user's login shell is bash, so
+ * I've made that behavior conditional on SSH_SOURCE_BASHRC being defined
+ * in config-top.h.
+ */
+#if 0
+ temp_var = find_variable ("SSH_CLIENT");
+ if (temp_var && imported_p (temp_var))
+ {
+ VUNSETATTR (temp_var, att_exported);
+ array_needs_making = 1;
+ }
+ temp_var = find_variable ("SSH2_CLIENT");
+ if (temp_var && imported_p (temp_var))
+ {
+ VUNSETATTR (temp_var, att_exported);
+ array_needs_making = 1;
+ }
+#endif
+
+ /* Get the user's real and effective user ids. */
+ uidset ();
+
+ temp_var = find_variable ("BASH_XTRACEFD");
+ if (temp_var && imported_p (temp_var))
+ sv_xtracefd (temp_var->name);
+
+ /* Initialize the dynamic variables, and seed their values. */
+ initialize_dynamic_variables ();
+}
+
+/* **************************************************************** */
+/* */
+/* Setting values for special shell variables */
+/* */
+/* **************************************************************** */
+
+static void
+set_machine_vars ()
+{
+ SHELL_VAR *temp_var;
+
+ temp_var = set_if_not ("HOSTTYPE", HOSTTYPE);
+ temp_var = set_if_not ("OSTYPE", OSTYPE);
+ temp_var = set_if_not ("MACHTYPE", MACHTYPE);
+
+ temp_var = set_if_not ("HOSTNAME", current_host_name);
+}
+
+/* Set $HOME to the information in the password file if we didn't get
+ it from the environment. */
+
+/* This function is not static so the tilde and readline libraries can
+ use it. */
+char *
+sh_get_home_dir ()
+{
+ if (current_user.home_dir == 0)
+ get_current_user_info ();
+ return current_user.home_dir;
+}
+
+static void
+set_home_var ()
+{
+ SHELL_VAR *temp_var;
+
+ temp_var = find_variable ("HOME");
+ if (temp_var == 0)
+ temp_var = bind_variable ("HOME", sh_get_home_dir (), 0);
+#if 0
+ VSETATTR (temp_var, att_exported);
+#endif
+}
+
+/* Set $SHELL to the user's login shell if it is not already set. Call
+ get_current_user_info if we haven't already fetched the shell. */
+static void
+set_shell_var ()
+{
+ SHELL_VAR *temp_var;
+
+ temp_var = find_variable ("SHELL");
+ if (temp_var == 0)
+ {
+ if (current_user.shell == 0)
+ get_current_user_info ();
+ temp_var = bind_variable ("SHELL", current_user.shell, 0);
+ }
+#if 0
+ VSETATTR (temp_var, att_exported);
+#endif
+}
+
+static char *
+get_bash_name ()
+{
+ char *name;
+
+ if ((login_shell == 1) && RELPATH(shell_name))
+ {
+ if (current_user.shell == 0)
+ get_current_user_info ();
+ name = savestring (current_user.shell);
+ }
+ else if (ABSPATH(shell_name))
+ name = savestring (shell_name);
+ else if (shell_name[0] == '.' && shell_name[1] == '/')
+ {
+ /* Fast path for common case. */
+ char *cdir;
+ int len;
+
+ cdir = get_string_value ("PWD");
+ if (cdir)
+ {
+ len = strlen (cdir);
+ name = (char *)xmalloc (len + strlen (shell_name) + 1);
+ strcpy (name, cdir);
+ strcpy (name + len, shell_name + 1);
+ }
+ else
+ name = savestring (shell_name);
+ }
+ else
+ {
+ char *tname;
+ int s;
+
+ tname = find_user_command (shell_name);
+
+ if (tname == 0)
+ {
+ /* Try the current directory. If there is not an executable
+ there, just punt and use the login shell. */
+ s = file_status (shell_name);
+ if (s & FS_EXECABLE)
+ {
+ tname = make_absolute (shell_name, get_string_value ("PWD"));
+ if (*shell_name == '.')
+ {
+ name = sh_canonpath (tname, PATH_CHECKDOTDOT|PATH_CHECKEXISTS);
+ if (name == 0)
+ name = tname;
+ else
+ free (tname);
+ }
+ else
+ name = tname;
+ }
+ else
+ {
+ if (current_user.shell == 0)
+ get_current_user_info ();
+ name = savestring (current_user.shell);
+ }
+ }
+ else
+ {
+ name = full_pathname (tname);
+ free (tname);
+ }
+ }
+
+ return (name);
+}
+
+void
+adjust_shell_level (change)
+ int change;
+{
+ char new_level[5], *old_SHLVL;
+ intmax_t old_level;
+ SHELL_VAR *temp_var;
+
+ old_SHLVL = get_string_value ("SHLVL");
+ if (old_SHLVL == 0 || *old_SHLVL == '\0' || legal_number (old_SHLVL, &old_level) == 0)
+ old_level = 0;
+
+ shell_level = old_level + change;
+ if (shell_level < 0)
+ shell_level = 0;
+ else if (shell_level > 1000)
+ {
+ internal_warning (_("shell level (%d) too high, resetting to 1"), shell_level);
+ shell_level = 1;
+ }
+
+ /* We don't need the full generality of itos here. */
+ if (shell_level < 10)
+ {
+ new_level[0] = shell_level + '0';
+ new_level[1] = '\0';
+ }
+ else if (shell_level < 100)
+ {
+ new_level[0] = (shell_level / 10) + '0';
+ new_level[1] = (shell_level % 10) + '0';
+ new_level[2] = '\0';
+ }
+ else if (shell_level < 1000)
+ {
+ new_level[0] = (shell_level / 100) + '0';
+ old_level = shell_level % 100;
+ new_level[1] = (old_level / 10) + '0';
+ new_level[2] = (old_level % 10) + '0';
+ new_level[3] = '\0';
+ }
+
+ temp_var = bind_variable ("SHLVL", new_level, 0);
+ set_auto_export (temp_var);
+}
+
+static void
+initialize_shell_level ()
+{
+ adjust_shell_level (1);
+}
+
+/* If we got PWD from the environment, update our idea of the current
+ working directory. In any case, make sure that PWD exists before
+ checking it. It is possible for getcwd () to fail on shell startup,
+ and in that case, PWD would be undefined. If this is an interactive
+ login shell, see if $HOME is the current working directory, and if
+ that's not the same string as $PWD, set PWD=$HOME. */
+
+void
+set_pwd ()
+{
+ SHELL_VAR *temp_var, *home_var;
+ char *temp_string, *home_string;
+
+ home_var = find_variable ("HOME");
+ home_string = home_var ? value_cell (home_var) : (char *)NULL;
+
+ temp_var = find_variable ("PWD");
+ if (temp_var && imported_p (temp_var) &&
+ (temp_string = value_cell (temp_var)) &&
+ same_file (temp_string, ".", (struct stat *)NULL, (struct stat *)NULL))
+ set_working_directory (temp_string);
+ else if (home_string && interactive_shell && login_shell &&
+ same_file (home_string, ".", (struct stat *)NULL, (struct stat *)NULL))
+ {
+ set_working_directory (home_string);
+ temp_var = bind_variable ("PWD", home_string, 0);
+ set_auto_export (temp_var);
+ }
+ else
+ {
+ temp_string = get_working_directory ("shell-init");
+ if (temp_string)
+ {
+ temp_var = bind_variable ("PWD", temp_string, 0);
+ set_auto_export (temp_var);
+ free (temp_string);
+ }
+ }
+
+ /* According to the Single Unix Specification, v2, $OLDPWD is an
+ `environment variable' and therefore should be auto-exported.
+ Make a dummy invisible variable for OLDPWD, and mark it as exported. */
+ temp_var = bind_variable ("OLDPWD", (char *)NULL, 0);
+ VSETATTR (temp_var, (att_exported | att_invisible));
+}
+
+/* Make a variable $PPID, which holds the pid of the shell's parent. */
+void
+set_ppid ()
+{
+ char namebuf[INT_STRLEN_BOUND(pid_t) + 1], *name;
+ SHELL_VAR *temp_var;
+
+ name = inttostr (getppid (), namebuf, sizeof(namebuf));
+ temp_var = find_variable ("PPID");
+ if (temp_var)
+ VUNSETATTR (temp_var, (att_readonly | att_exported));
+ temp_var = bind_variable ("PPID", name, 0);
+ VSETATTR (temp_var, (att_readonly | att_integer));
+}
+
+static void
+uidset ()
+{
+ char buff[INT_STRLEN_BOUND(uid_t) + 1], *b;
+ register SHELL_VAR *v;
+
+ b = inttostr (current_user.uid, buff, sizeof (buff));
+ v = find_variable ("UID");
+ if (v == 0)
+ {
+ v = bind_variable ("UID", b, 0);
+ VSETATTR (v, (att_readonly | att_integer));
+ }
+
+ if (current_user.euid != current_user.uid)
+ b = inttostr (current_user.euid, buff, sizeof (buff));
+
+ v = find_variable ("EUID");
+ if (v == 0)
+ {
+ v = bind_variable ("EUID", b, 0);
+ VSETATTR (v, (att_readonly | att_integer));
+ }
+}
+
+#if defined (ARRAY_VARS)
+static void
+make_vers_array ()
+{
+ SHELL_VAR *vv;
+ ARRAY *av;
+ char *s, d[32], b[INT_STRLEN_BOUND(int) + 1];
+
+ unbind_variable ("BASH_VERSINFO");
+
+ vv = make_new_array_variable ("BASH_VERSINFO");
+ av = array_cell (vv);
+ strcpy (d, dist_version);
+ s = strchr (d, '.');
+ if (s)
+ *s++ = '\0';
+ array_insert (av, 0, d);
+ array_insert (av, 1, s);
+ s = inttostr (patch_level, b, sizeof (b));
+ array_insert (av, 2, s);
+ s = inttostr (build_version, b, sizeof (b));
+ array_insert (av, 3, s);
+ array_insert (av, 4, release_status);
+ array_insert (av, 5, MACHTYPE);
+
+ VSETATTR (vv, att_readonly);
+}
+#endif /* ARRAY_VARS */
+
+/* Set the environment variables $LINES and $COLUMNS in response to
+ a window size change. */
+void
+sh_set_lines_and_columns (lines, cols)
+ int lines, cols;
+{
+ char val[INT_STRLEN_BOUND(int) + 1], *v;
+
+#if defined (READLINE)
+ /* If we are currently assigning to LINES or COLUMNS, don't do anything. */
+ if (winsize_assignment)
+ return;
+#endif
+
+ v = inttostr (lines, val, sizeof (val));
+ bind_variable ("LINES", v, 0);
+
+ v = inttostr (cols, val, sizeof (val));
+ bind_variable ("COLUMNS", v, 0);
+}
+
+/* **************************************************************** */
+/* */
+/* Printing variables and values */
+/* */
+/* **************************************************************** */
+
+/* Print LIST (a list of shell variables) to stdout in such a way that
+ they can be read back in. */
+void
+print_var_list (list)
+ register SHELL_VAR **list;
+{
+ register int i;
+ register SHELL_VAR *var;
+
+ for (i = 0; list && (var = list[i]); i++)
+ if (invisible_p (var) == 0)
+ print_assignment (var);
+}
+
+/* Print LIST (a list of shell functions) to stdout in such a way that
+ they can be read back in. */
+void
+print_func_list (list)
+ register SHELL_VAR **list;
+{
+ register int i;
+ register SHELL_VAR *var;
+
+ for (i = 0; list && (var = list[i]); i++)
+ {
+ printf ("%s ", var->name);
+ print_var_function (var);
+ printf ("\n");
+ }
+}
+
+/* Print the value of a single SHELL_VAR. No newline is
+ output, but the variable is printed in such a way that
+ it can be read back in. */
+void
+print_assignment (var)
+ SHELL_VAR *var;
+{
+ if (var_isset (var) == 0)
+ return;
+
+ if (function_p (var))
+ {
+ printf ("%s", var->name);
+ print_var_function (var);
+ printf ("\n");
+ }
+#if defined (ARRAY_VARS)
+ else if (array_p (var))
+ print_array_assignment (var, 0);
+ else if (assoc_p (var))
+ print_assoc_assignment (var, 0);
+#endif /* ARRAY_VARS */
+ else
+ {
+ printf ("%s=", var->name);
+ print_var_value (var, 1);
+ printf ("\n");
+ }
+}
+
+/* Print the value cell of VAR, a shell variable. Do not print
+ the name, nor leading/trailing newline. If QUOTE is non-zero,
+ and the value contains shell metacharacters, quote the value
+ in such a way that it can be read back in. */
+void
+print_var_value (var, quote)
+ SHELL_VAR *var;
+ int quote;
+{
+ char *t;
+
+ if (var_isset (var) == 0)
+ return;
+
+ if (quote && posixly_correct == 0 && ansic_shouldquote (value_cell (var)))
+ {
+ t = ansic_quote (value_cell (var), 0, (int *)0);
+ printf ("%s", t);
+ free (t);
+ }
+ else if (quote && sh_contains_shell_metas (value_cell (var)))
+ {
+ t = sh_single_quote (value_cell (var));
+ printf ("%s", t);
+ free (t);
+ }
+ else
+ printf ("%s", value_cell (var));
+}
+
+/* Print the function cell of VAR, a shell variable. Do not
+ print the name, nor leading/trailing newline. */
+void
+print_var_function (var)
+ SHELL_VAR *var;
+{
+ char *x;
+
+ if (function_p (var) && var_isset (var))
+ {
+ x = named_function_string ((char *)NULL, function_cell(var), FUNC_MULTILINE|FUNC_EXTERNAL);
+ printf ("%s", x);
+ }
+}
+
+/* **************************************************************** */
+/* */
+/* Dynamic Variables */
+/* */
+/* **************************************************************** */
+
+/* DYNAMIC VARIABLES
+
+ These are variables whose values are generated anew each time they are
+ referenced. These are implemented using a pair of function pointers
+ in the struct variable: assign_func, which is called from bind_variable
+ and, if arrays are compiled into the shell, some of the functions in
+ arrayfunc.c, and dynamic_value, which is called from find_variable.
+
+ assign_func is called from bind_variable_internal, if
+ bind_variable_internal discovers that the variable being assigned to
+ has such a function. The function is called as
+ SHELL_VAR *temp = (*(entry->assign_func)) (entry, value, ind)
+ and the (SHELL_VAR *)temp is returned as the value of bind_variable. It
+ is usually ENTRY (self). IND is an index for an array variable, and
+ unused otherwise.
+
+ dynamic_value is called from find_variable_internal to return a `new'
+ value for the specified dynamic varible. If this function is NULL,
+ the variable is treated as a `normal' shell variable. If it is not,
+ however, then this function is called like this:
+ tempvar = (*(var->dynamic_value)) (var);
+
+ Sometimes `tempvar' will replace the value of `var'. Other times, the
+ shell will simply use the string value. Pretty object-oriented, huh?
+
+ Be warned, though: if you `unset' a special variable, it loses its
+ special meaning, even if you subsequently set it.
+
+ The special assignment code would probably have been better put in
+ subst.c: do_assignment_internal, in the same style as
+ stupidly_hack_special_variables, but I wanted the changes as
+ localized as possible. */
+
+#define INIT_DYNAMIC_VAR(var, val, gfunc, afunc) \
+ do \
+ { \
+ v = bind_variable (var, (val), 0); \
+ v->dynamic_value = gfunc; \
+ v->assign_func = afunc; \
+ } \
+ while (0)
+
+#define INIT_DYNAMIC_ARRAY_VAR(var, gfunc, afunc) \
+ do \
+ { \
+ v = make_new_array_variable (var); \
+ v->dynamic_value = gfunc; \
+ v->assign_func = afunc; \
+ } \
+ while (0)
+
+#define INIT_DYNAMIC_ASSOC_VAR(var, gfunc, afunc) \
+ do \
+ { \
+ v = make_new_assoc_variable (var); \
+ v->dynamic_value = gfunc; \
+ v->assign_func = afunc; \
+ } \
+ while (0)
+
+static SHELL_VAR *
+null_assign (self, value, unused, key)
+ SHELL_VAR *self;
+ char *value;
+ arrayind_t unused;
+ char *key;
+{
+ return (self);
+}
+
+#if defined (ARRAY_VARS)
+static SHELL_VAR *
+null_array_assign (self, value, ind, key)
+ SHELL_VAR *self;
+ char *value;
+ arrayind_t ind;
+ char *key;
+{
+ return (self);
+}
+#endif
+
+/* Degenerate `dynamic_value' function; just returns what's passed without
+ manipulation. */
+static SHELL_VAR *
+get_self (self)
+ SHELL_VAR *self;
+{
+ return (self);
+}
+
+#if defined (ARRAY_VARS)
+/* A generic dynamic array variable initializer. Initialize array variable
+ NAME with dynamic value function GETFUNC and assignment function SETFUNC. */
+static SHELL_VAR *
+init_dynamic_array_var (name, getfunc, setfunc, attrs)
+ char *name;
+ sh_var_value_func_t *getfunc;
+ sh_var_assign_func_t *setfunc;
+ int attrs;
+{
+ SHELL_VAR *v;
+
+ v = find_variable (name);
+ if (v)
+ return (v);
+ INIT_DYNAMIC_ARRAY_VAR (name, getfunc, setfunc);
+ if (attrs)
+ VSETATTR (v, attrs);
+ return v;
+}
+
+static SHELL_VAR *
+init_dynamic_assoc_var (name, getfunc, setfunc, attrs)
+ char *name;
+ sh_var_value_func_t *getfunc;
+ sh_var_assign_func_t *setfunc;
+ int attrs;
+{
+ SHELL_VAR *v;
+
+ v = find_variable (name);
+ if (v)
+ return (v);
+ INIT_DYNAMIC_ASSOC_VAR (name, getfunc, setfunc);
+ if (attrs)
+ VSETATTR (v, attrs);
+ return v;
+}
+#endif
+
+/* The value of $SECONDS. This is the number of seconds since shell
+ invocation, or, the number of seconds since the last assignment + the
+ value of the last assignment. */
+static intmax_t seconds_value_assigned;
+
+static SHELL_VAR *
+assign_seconds (self, value, unused, key)
+ SHELL_VAR *self;
+ char *value;
+ arrayind_t unused;
+ char *key;
+{
+ if (legal_number (value, &seconds_value_assigned) == 0)
+ seconds_value_assigned = 0;
+ shell_start_time = NOW;
+ return (self);
+}
+
+static SHELL_VAR *
+get_seconds (var)
+ SHELL_VAR *var;
+{
+ time_t time_since_start;
+ char *p;
+
+ time_since_start = NOW - shell_start_time;
+ p = itos(seconds_value_assigned + time_since_start);
+
+ FREE (value_cell (var));
+
+ VSETATTR (var, att_integer);
+ var_setvalue (var, p);
+ return (var);
+}
+
+static SHELL_VAR *
+init_seconds_var ()
+{
+ SHELL_VAR *v;
+
+ v = find_variable ("SECONDS");
+ if (v)
+ {
+ if (legal_number (value_cell(v), &seconds_value_assigned) == 0)
+ seconds_value_assigned = 0;
+ }
+ INIT_DYNAMIC_VAR ("SECONDS", (v ? value_cell (v) : (char *)NULL), get_seconds, assign_seconds);
+ return v;
+}
+
+/* The random number seed. You can change this by setting RANDOM. */
+static unsigned long rseed = 1;
+static int last_random_value;
+static int seeded_subshell = 0;
+
+/* A linear congruential random number generator based on the example
+ one in the ANSI C standard. This one isn't very good, but a more
+ complicated one is overkill. */
+
+/* Returns a pseudo-random number between 0 and 32767. */
+static int
+brand ()
+{
+ /* From "Random number generators: good ones are hard to find",
+ Park and Miller, Communications of the ACM, vol. 31, no. 10,
+ October 1988, p. 1195. filtered through FreeBSD */
+ long h, l;
+
+ /* Can't seed with 0. */
+ if (rseed == 0)
+ rseed = 123459876;
+ h = rseed / 127773;
+ l = rseed % 127773;
+ rseed = 16807 * l - 2836 * h;
+#if 0
+ if (rseed < 0)
+ rseed += 0x7fffffff;
+#endif
+ return ((unsigned int)(rseed & 32767)); /* was % 32768 */
+}
+
+/* Set the random number generator seed to SEED. */
+static void
+sbrand (seed)
+ unsigned long seed;
+{
+ rseed = seed;
+ last_random_value = 0;
+}
+
+static void
+seedrand ()
+{
+ struct timeval tv;
+
+ gettimeofday (&tv, NULL);
+ sbrand (tv.tv_sec ^ tv.tv_usec ^ getpid ());
+}
+
+static SHELL_VAR *
+assign_random (self, value, unused, key)
+ SHELL_VAR *self;
+ char *value;
+ arrayind_t unused;
+ char *key;
+{
+ sbrand (strtoul (value, (char **)NULL, 10));
+ if (subshell_environment)
+ seeded_subshell = getpid ();
+ return (self);
+}
+
+int
+get_random_number ()
+{
+ int rv, pid;
+
+ /* Reset for command and process substitution. */
+ pid = getpid ();
+ if (subshell_environment && seeded_subshell != pid)
+ {
+ seedrand ();
+ seeded_subshell = pid;
+ }
+
+ do
+ rv = brand ();
+ while (rv == last_random_value);
+ return rv;
+}
+
+static SHELL_VAR *
+get_random (var)
+ SHELL_VAR *var;
+{
+ int rv;
+ char *p;
+
+ rv = get_random_number ();
+ last_random_value = rv;
+ p = itos (rv);
+
+ FREE (value_cell (var));
+
+ VSETATTR (var, att_integer);
+ var_setvalue (var, p);
+ return (var);
+}
+
+static SHELL_VAR *
+assign_lineno (var, value, unused, key)
+ SHELL_VAR *var;
+ char *value;
+ arrayind_t unused;
+ char *key;
+{
+ intmax_t new_value;
+
+ if (value == 0 || *value == '\0' || legal_number (value, &new_value) == 0)
+ new_value = 0;
+ line_number = line_number_base = new_value;
+ return var;
+}
+
+/* Function which returns the current line number. */
+static SHELL_VAR *
+get_lineno (var)
+ SHELL_VAR *var;
+{
+ char *p;
+ int ln;
+
+ ln = executing_line_number ();
+ p = itos (ln);
+ FREE (value_cell (var));
+ var_setvalue (var, p);
+ return (var);
+}
+
+static SHELL_VAR *
+assign_subshell (var, value, unused, key)
+ SHELL_VAR *var;
+ char *value;
+ arrayind_t unused;
+ char *key;
+{
+ intmax_t new_value;
+
+ if (value == 0 || *value == '\0' || legal_number (value, &new_value) == 0)
+ new_value = 0;
+ subshell_level = new_value;
+ return var;
+}
+
+static SHELL_VAR *
+get_subshell (var)
+ SHELL_VAR *var;
+{
+ char *p;
+
+ p = itos (subshell_level);
+ FREE (value_cell (var));
+ var_setvalue (var, p);
+ return (var);
+}
+
+static SHELL_VAR *
+get_bashpid (var)
+ SHELL_VAR *var;
+{
+ int pid;
+ char *p;
+
+ pid = getpid ();
+ p = itos (pid);
+
+ FREE (value_cell (var));
+ VSETATTR (var, att_integer|att_readonly);
+ var_setvalue (var, p);
+ return (var);
+}
+
+static SHELL_VAR *
+get_bash_command (var)
+ SHELL_VAR *var;
+{
+ char *p;
+
+ if (the_printed_command_except_trap)
+ p = savestring (the_printed_command_except_trap);
+ else
+ {
+ p = (char *)xmalloc (1);
+ p[0] = '\0';
+ }
+ FREE (value_cell (var));
+ var_setvalue (var, p);
+ return (var);
+}
+
+#if defined (HISTORY)
+static SHELL_VAR *
+get_histcmd (var)
+ SHELL_VAR *var;
+{
+ char *p;
+
+ p = itos (history_number ());
+ FREE (value_cell (var));
+ var_setvalue (var, p);
+ return (var);
+}
+#endif
+
+#if defined (READLINE)
+/* When this function returns, VAR->value points to malloced memory. */
+static SHELL_VAR *
+get_comp_wordbreaks (var)
+ SHELL_VAR *var;
+{
+ /* If we don't have anything yet, assign a default value. */
+ if (rl_completer_word_break_characters == 0 && bash_readline_initialized == 0)
+ enable_hostname_completion (perform_hostname_completion);
+
+ FREE (value_cell (var));
+ var_setvalue (var, savestring (rl_completer_word_break_characters));
+
+ return (var);
+}
+
+/* When this function returns, rl_completer_word_break_characters points to
+ malloced memory. */
+static SHELL_VAR *
+assign_comp_wordbreaks (self, value, unused, key)
+ SHELL_VAR *self;
+ char *value;
+ arrayind_t unused;
+ char *key;
+{
+ if (rl_completer_word_break_characters &&
+ rl_completer_word_break_characters != rl_basic_word_break_characters)
+ free (rl_completer_word_break_characters);
+
+ rl_completer_word_break_characters = savestring (value);
+ return self;
+}
+#endif /* READLINE */
+
+#if defined (PUSHD_AND_POPD) && defined (ARRAY_VARS)
+static SHELL_VAR *
+assign_dirstack (self, value, ind, key)
+ SHELL_VAR *self;
+ char *value;
+ arrayind_t ind;
+ char *key;
+{
+ set_dirstack_element (ind, 1, value);
+ return self;
+}
+
+static SHELL_VAR *
+get_dirstack (self)
+ SHELL_VAR *self;
+{
+ ARRAY *a;
+ WORD_LIST *l;
+
+ l = get_directory_stack (0);
+ a = array_from_word_list (l);
+ array_dispose (array_cell (self));
+ dispose_words (l);
+ var_setarray (self, a);
+ return self;
+}
+#endif /* PUSHD AND POPD && ARRAY_VARS */
+
+#if defined (ARRAY_VARS)
+/* We don't want to initialize the group set with a call to getgroups()
+ unless we're asked to, but we only want to do it once. */
+static SHELL_VAR *
+get_groupset (self)
+ SHELL_VAR *self;
+{
+ register int i;
+ int ng;
+ ARRAY *a;
+ static char **group_set = (char **)NULL;
+
+ if (group_set == 0)
+ {
+ group_set = get_group_list (&ng);
+ a = array_cell (self);
+ for (i = 0; i < ng; i++)
+ array_insert (a, i, group_set[i]);
+ }
+ return (self);
+}
+
+static SHELL_VAR *
+build_hashcmd (self)
+ SHELL_VAR *self;
+{
+ HASH_TABLE *h;
+ int i;
+ char *k, *v;
+ BUCKET_CONTENTS *item;
+
+ h = assoc_cell (self);
+ if (h)
+ assoc_dispose (h);
+
+ if (hashed_filenames == 0 || HASH_ENTRIES (hashed_filenames) == 0)
+ {
+ var_setvalue (self, (char *)NULL);
+ return self;
+ }
+
+ h = assoc_create (hashed_filenames->nbuckets);
+ for (i = 0; i < hashed_filenames->nbuckets; i++)
+ {
+ for (item = hash_items (i, hashed_filenames); item; item = item->next)
+ {
+ k = savestring (item->key);
+ v = pathdata(item)->path;
+ assoc_insert (h, k, v);
+ }
+ }
+
+ var_setvalue (self, (char *)h);
+ return self;
+}
+
+static SHELL_VAR *
+get_hashcmd (self)
+ SHELL_VAR *self;
+{
+ build_hashcmd (self);
+ return (self);
+}
+
+static SHELL_VAR *
+assign_hashcmd (self, value, ind, key)
+ SHELL_VAR *self;
+ char *value;
+ arrayind_t ind;
+ char *key;
+{
+ phash_insert (key, value, 0, 0);
+ return (build_hashcmd (self));
+}
+
+#if defined (ALIAS)
+static SHELL_VAR *
+build_aliasvar (self)
+ SHELL_VAR *self;
+{
+ HASH_TABLE *h;
+ int i;
+ char *k, *v;
+ BUCKET_CONTENTS *item;
+
+ h = assoc_cell (self);
+ if (h)
+ assoc_dispose (h);
+
+ if (aliases == 0 || HASH_ENTRIES (aliases) == 0)
+ {
+ var_setvalue (self, (char *)NULL);
+ return self;
+ }
+
+ h = assoc_create (aliases->nbuckets);
+ for (i = 0; i < aliases->nbuckets; i++)
+ {
+ for (item = hash_items (i, aliases); item; item = item->next)
+ {
+ k = savestring (item->key);
+ v = ((alias_t *)(item->data))->value;
+ assoc_insert (h, k, v);
+ }
+ }
+
+ var_setvalue (self, (char *)h);
+ return self;
+}
+
+static SHELL_VAR *
+get_aliasvar (self)
+ SHELL_VAR *self;
+{
+ build_aliasvar (self);
+ return (self);
+}
+
+static SHELL_VAR *
+assign_aliasvar (self, value, ind, key)
+ SHELL_VAR *self;
+ char *value;
+ arrayind_t ind;
+ char *key;
+{
+ add_alias (key, value);
+ return (build_aliasvar (self));
+}
+#endif /* ALIAS */
+
+#endif /* ARRAY_VARS */
+
+/* If ARRAY_VARS is not defined, this just returns the name of any
+ currently-executing function. If we have arrays, it's a call stack. */
+static SHELL_VAR *
+get_funcname (self)
+ SHELL_VAR *self;
+{
+#if ! defined (ARRAY_VARS)
+ char *t;
+ if (variable_context && this_shell_function)
+ {
+ FREE (value_cell (self));
+ t = savestring (this_shell_function->name);
+ var_setvalue (self, t);
+ }
+#endif
+ return (self);
+}
+
+void
+make_funcname_visible (on_or_off)
+ int on_or_off;
+{
+ SHELL_VAR *v;
+
+ v = find_variable ("FUNCNAME");
+ if (v == 0 || v->dynamic_value == 0)
+ return;
+
+ if (on_or_off)
+ VUNSETATTR (v, att_invisible);
+ else
+ VSETATTR (v, att_invisible);
+}
+
+static SHELL_VAR *
+init_funcname_var ()
+{
+ SHELL_VAR *v;
+
+ v = find_variable ("FUNCNAME");
+ if (v)
+ return v;
+#if defined (ARRAY_VARS)
+ INIT_DYNAMIC_ARRAY_VAR ("FUNCNAME", get_funcname, null_array_assign);
+#else
+ INIT_DYNAMIC_VAR ("FUNCNAME", (char *)NULL, get_funcname, null_assign);
+#endif
+ VSETATTR (v, att_invisible|att_noassign);
+ return v;
+}
+
+static void
+initialize_dynamic_variables ()
+{
+ SHELL_VAR *v;
+
+ v = init_seconds_var ();
+
+ INIT_DYNAMIC_VAR ("BASH_COMMAND", (char *)NULL, get_bash_command, (sh_var_assign_func_t *)NULL);
+ INIT_DYNAMIC_VAR ("BASH_SUBSHELL", (char *)NULL, get_subshell, assign_subshell);
+
+ INIT_DYNAMIC_VAR ("RANDOM", (char *)NULL, get_random, assign_random);
+ VSETATTR (v, att_integer);
+ INIT_DYNAMIC_VAR ("LINENO", (char *)NULL, get_lineno, assign_lineno);
+ VSETATTR (v, att_integer);
+
+ INIT_DYNAMIC_VAR ("BASHPID", (char *)NULL, get_bashpid, null_assign);
+ VSETATTR (v, att_integer|att_readonly);
+
+#if defined (HISTORY)
+ INIT_DYNAMIC_VAR ("HISTCMD", (char *)NULL, get_histcmd, (sh_var_assign_func_t *)NULL);
+ VSETATTR (v, att_integer);
+#endif
+
+#if defined (READLINE)
+ INIT_DYNAMIC_VAR ("COMP_WORDBREAKS", (char *)NULL, get_comp_wordbreaks, assign_comp_wordbreaks);
+#endif
+
+#if defined (PUSHD_AND_POPD) && defined (ARRAY_VARS)
+ v = init_dynamic_array_var ("DIRSTACK", get_dirstack, assign_dirstack, 0);
+#endif /* PUSHD_AND_POPD && ARRAY_VARS */
+
+#if defined (ARRAY_VARS)
+ v = init_dynamic_array_var ("GROUPS", get_groupset, null_array_assign, att_noassign);
+
+# if defined (DEBUGGER)
+ v = init_dynamic_array_var ("BASH_ARGC", get_self, null_array_assign, att_noassign|att_nounset);
+ v = init_dynamic_array_var ("BASH_ARGV", get_self, null_array_assign, att_noassign|att_nounset);
+# endif /* DEBUGGER */
+ v = init_dynamic_array_var ("BASH_SOURCE", get_self, null_array_assign, att_noassign|att_nounset);
+ v = init_dynamic_array_var ("BASH_LINENO", get_self, null_array_assign, att_noassign|att_nounset);
+
+ v = init_dynamic_assoc_var ("BASH_CMDS", get_hashcmd, assign_hashcmd, att_nofree);
+# if defined (ALIAS)
+ v = init_dynamic_assoc_var ("BASH_ALIASES", get_aliasvar, assign_aliasvar, att_nofree);
+# endif
+#endif
+
+ v = init_funcname_var ();
+}
+
+/* **************************************************************** */
+/* */
+/* Retrieving variables and values */
+/* */
+/* **************************************************************** */
+
+/* How to get a pointer to the shell variable or function named NAME.
+ HASHED_VARS is a pointer to the hash table containing the list
+ of interest (either variables or functions). */
+
+static SHELL_VAR *
+hash_lookup (name, hashed_vars)
+ const char *name;
+ HASH_TABLE *hashed_vars;
+{
+ BUCKET_CONTENTS *bucket;
+
+ bucket = hash_search (name, hashed_vars, 0);
+ /* If we find the name in HASHED_VARS, set LAST_TABLE_SEARCHED to that
+ table. */
+ if (bucket)
+ last_table_searched = hashed_vars;
+ return (bucket ? (SHELL_VAR *)bucket->data : (SHELL_VAR *)NULL);
+}
+
+SHELL_VAR *
+var_lookup (name, vcontext)
+ const char *name;
+ VAR_CONTEXT *vcontext;
+{
+ VAR_CONTEXT *vc;
+ SHELL_VAR *v;
+
+ v = (SHELL_VAR *)NULL;
+ for (vc = vcontext; vc; vc = vc->down)
+ if (v = hash_lookup (name, vc->table))
+ break;
+
+ return v;
+}
+
+/* Look up the variable entry named NAME. If SEARCH_TEMPENV is non-zero,
+ then also search the temporarily built list of exported variables.
+ The lookup order is:
+ temporary_env
+ shell_variables list
+*/
+
+SHELL_VAR *
+find_variable_internal (name, flags)
+ const char *name;
+ int flags;
+{
+ SHELL_VAR *var;
+ int search_tempenv, force_tempenv;
+ VAR_CONTEXT *vc;
+
+ var = (SHELL_VAR *)NULL;
+
+ force_tempenv = (flags & FV_FORCETEMPENV);
+
+ /* If explicitly requested, first look in the temporary environment for
+ the variable. This allows constructs such as "foo=x eval 'echo $foo'"
+ to get the `exported' value of $foo. This happens if we are executing
+ a function or builtin, or if we are looking up a variable in a
+ "subshell environment". */
+ search_tempenv = force_tempenv || (expanding_redir == 0 && subshell_environment);
+
+ if (search_tempenv && temporary_env)
+ var = hash_lookup (name, temporary_env);
+
+ if (var == 0)
+ {
+ if ((flags & FV_SKIPINVISIBLE) == 0)
+ var = var_lookup (name, shell_variables);
+ else
+ {
+ /* essentially var_lookup expanded inline so we can check for
+ att_invisible */
+ for (vc = shell_variables; vc; vc = vc->down)
+ {
+ var = hash_lookup (name, vc->table);
+ if (var && invisible_p (var))
+ var = 0;
+ if (var)
+ break;
+ }
+ }
+ }
+
+ if (var == 0)
+ return ((SHELL_VAR *)NULL);
+
+ return (var->dynamic_value ? (*(var->dynamic_value)) (var) : var);
+}
+
+/* Look up and resolve the chain of nameref variables starting at V all the
+ way to NULL or non-nameref. */
+SHELL_VAR *
+find_variable_nameref (v)
+ SHELL_VAR *v;
+{
+ int level, flags;
+ char *newname;
+ SHELL_VAR *orig, *oldv;
+
+ level = 0;
+ orig = v;
+ while (v && nameref_p (v))
+ {
+ level++;
+ if (level > NAMEREF_MAX)
+ return ((SHELL_VAR *)0); /* error message here? */
+ newname = nameref_cell (v);
+ if (newname == 0 || *newname == '\0')
+ return ((SHELL_VAR *)0);
+ oldv = v;
+ flags = 0;
+ if (expanding_redir == 0 && (assigning_in_environment || executing_builtin))
+ flags |= FV_FORCETEMPENV;
+ v = find_variable_internal (newname, flags);
+ if (v == orig || v == oldv)
+ {
+ internal_warning (_("%s: circular name reference"), orig->name);
+ return ((SHELL_VAR *)0);
+ }
+ }
+ return v;
+}
+
+/* Resolve the chain of nameref variables for NAME. XXX - could change later */
+SHELL_VAR *
+find_variable_last_nameref (name)
+ const char *name;
+{
+ SHELL_VAR *v, *nv;
+ char *newname;
+ int level, flags;
+
+ nv = v = find_variable_noref (name);
+ level = 0;
+ while (v && nameref_p (v))
+ {
+ level++;
+ if (level > NAMEREF_MAX)
+ return ((SHELL_VAR *)0); /* error message here? */
+ newname = nameref_cell (v);
+ if (newname == 0 || *newname == '\0')
+ return ((SHELL_VAR *)0);
+ nv = v;
+ flags = 0;
+ if (expanding_redir == 0 && (assigning_in_environment || executing_builtin))
+ flags |= FV_FORCETEMPENV;
+ v = find_variable_internal (newname, flags);
+ }
+ return nv;
+}
+
+/* Resolve the chain of nameref variables for NAME. XXX - could change later */
+SHELL_VAR *
+find_global_variable_last_nameref (name)
+ const char *name;
+{
+ SHELL_VAR *v, *nv;
+ char *newname;
+ int level;
+
+ nv = v = find_global_variable_noref (name);
+ level = 0;
+ while (v && nameref_p (v))
+ {
+ level++;
+ if (level > NAMEREF_MAX)
+ return ((SHELL_VAR *)0); /* error message here? */
+ newname = nameref_cell (v);
+ if (newname == 0 || *newname == '\0')
+ return ((SHELL_VAR *)0);
+ nv = v;
+ v = find_global_variable_noref (newname);
+ }
+ return nv;
+}
+
+static SHELL_VAR *
+find_nameref_at_context (v, vc)
+ SHELL_VAR *v;
+ VAR_CONTEXT *vc;
+{
+ SHELL_VAR *nv, *nv2;
+ VAR_CONTEXT *nvc;
+ char *newname;
+ int level;
+
+ nv = v;
+ level = 1;
+ while (nv && nameref_p (nv))
+ {
+ level++;
+ if (level > NAMEREF_MAX)
+ return ((SHELL_VAR *)NULL);
+ newname = nameref_cell (nv);
+ if (newname == 0 || *newname == '\0')
+ return ((SHELL_VAR *)NULL);
+ nv2 = hash_lookup (newname, vc->table);
+ if (nv2 == 0)
+ break;
+ nv = nv2;
+ }
+ return nv;
+}
+
+/* Do nameref resolution from the VC, which is the local context for some
+ function or builtin, `up' the chain to the global variables context. If
+ NVCP is not NULL, return the variable context where we finally ended the
+ nameref resolution (so the bind_variable_internal can use the correct
+ variable context and hash table). */
+static SHELL_VAR *
+find_variable_nameref_context (v, vc, nvcp)
+ SHELL_VAR *v;
+ VAR_CONTEXT *vc;
+ VAR_CONTEXT **nvcp;
+{
+ SHELL_VAR *nv, *nv2;
+ VAR_CONTEXT *nvc;
+
+ /* Look starting at the current context all the way `up' */
+ for (nv = v, nvc = vc; nvc; nvc = nvc->down)
+ {
+ nv2 = find_nameref_at_context (nv, nvc);
+ if (nv2 == 0)
+ continue;
+ nv = nv2;
+ if (*nvcp)
+ *nvcp = nvc;
+ if (nameref_p (nv) == 0)
+ break;
+ }
+ return (nameref_p (nv) ? (SHELL_VAR *)NULL : nv);
+}
+
+/* Do nameref resolution from the VC, which is the local context for some
+ function or builtin, `up' the chain to the global variables context. If
+ NVCP is not NULL, return the variable context where we finally ended the
+ nameref resolution (so the bind_variable_internal can use the correct
+ variable context and hash table). */
+static SHELL_VAR *
+find_variable_last_nameref_context (v, vc, nvcp)
+ SHELL_VAR *v;
+ VAR_CONTEXT *vc;
+ VAR_CONTEXT **nvcp;
+{
+ SHELL_VAR *nv, *nv2;
+ VAR_CONTEXT *nvc;
+
+ /* Look starting at the current context all the way `up' */
+ for (nv = v, nvc = vc; nvc; nvc = nvc->down)
+ {
+ nv2 = find_nameref_at_context (nv, nvc);
+ if (nv2 == 0)
+ continue;
+ nv = nv2;
+ if (*nvcp)
+ *nvcp = nvc;
+ }
+ return (nameref_p (nv) ? nv : (SHELL_VAR *)NULL);
+}
+
+/* Find a variable, forcing a search of the temporary environment first */
+SHELL_VAR *
+find_variable_tempenv (name)
+ const char *name;
+{
+ SHELL_VAR *var;
+
+ var = find_variable_internal (name, FV_FORCETEMPENV);
+ if (var && nameref_p (var))
+ var = find_variable_nameref (var);
+ return (var);
+}
+
+/* Find a variable, not forcing a search of the temporary environment first */
+SHELL_VAR *
+find_variable_notempenv (name)
+ const char *name;
+{
+ SHELL_VAR *var;
+
+ var = find_variable_internal (name, 0);
+ if (var && nameref_p (var))
+ var = find_variable_nameref (var);
+ return (var);
+}
+
+SHELL_VAR *
+find_global_variable (name)
+ const char *name;
+{
+ SHELL_VAR *var;
+
+ var = var_lookup (name, global_variables);
+ if (var && nameref_p (var))
+ var = find_variable_nameref (var);
+
+ if (var == 0)
+ return ((SHELL_VAR *)NULL);
+
+ return (var->dynamic_value ? (*(var->dynamic_value)) (var) : var);
+}
+
+SHELL_VAR *
+find_global_variable_noref (name)
+ const char *name;
+{
+ SHELL_VAR *var;
+
+ var = var_lookup (name, global_variables);
+
+ if (var == 0)
+ return ((SHELL_VAR *)NULL);
+
+ return (var->dynamic_value ? (*(var->dynamic_value)) (var) : var);
+}
+
+SHELL_VAR *
+find_shell_variable (name)
+ const char *name;
+{
+ SHELL_VAR *var;
+
+ var = var_lookup (name, shell_variables);
+ if (var && nameref_p (var))
+ var = find_variable_nameref (var);
+
+ if (var == 0)
+ return ((SHELL_VAR *)NULL);
+
+ return (var->dynamic_value ? (*(var->dynamic_value)) (var) : var);
+}
+
+/* Look up the variable entry named NAME. Returns the entry or NULL. */
+SHELL_VAR *
+find_variable (name)
+ const char *name;
+{
+ SHELL_VAR *v;
+ int flags;
+
+ last_table_searched = 0;
+ flags = 0;
+ if (expanding_redir == 0 && (assigning_in_environment || executing_builtin))
+ flags |= FV_FORCETEMPENV;
+ v = find_variable_internal (name, flags);
+ if (v && nameref_p (v))
+ v = find_variable_nameref (v);
+ return v;
+}
+
+/* Find the first instance of NAME in the variable context chain; return first
+ one found without att_invisible set; return 0 if no non-invisible instances
+ found. */
+SHELL_VAR *
+find_variable_no_invisible (name)
+ const char *name;
+{
+ SHELL_VAR *v;
+ int flags;
+
+ last_table_searched = 0;
+ flags = FV_SKIPINVISIBLE;
+ if (expanding_redir == 0 && (assigning_in_environment || executing_builtin))
+ flags |= FV_FORCETEMPENV;
+ v = find_variable_internal (name, flags);
+ if (v && nameref_p (v))
+ v = find_variable_nameref (v);
+ return v;
+}
+
+/* Find the first instance of NAME in the variable context chain; return first
+ one found even if att_invisible set. */
+SHELL_VAR *
+find_variable_for_assignment (name)
+ const char *name;
+{
+ SHELL_VAR *v;
+ int flags;
+
+ last_table_searched = 0;
+ flags = 0;
+ if (expanding_redir == 0 && (assigning_in_environment || executing_builtin))
+ flags |= FV_FORCETEMPENV;
+ v = find_variable_internal (name, flags);
+ if (v && nameref_p (v))
+ v = find_variable_nameref (v);
+ return v;
+}
+
+SHELL_VAR *
+find_variable_noref (name)
+ const char *name;
+{
+ SHELL_VAR *v;
+ int flags;
+
+ flags = 0;
+ if (expanding_redir == 0 && (assigning_in_environment || executing_builtin))
+ flags |= FV_FORCETEMPENV;
+ v = find_variable_internal (name, flags);
+ return v;
+}
+
+/* Look up the function entry whose name matches STRING.
+ Returns the entry or NULL. */
+SHELL_VAR *
+find_function (name)
+ const char *name;
+{
+ return (hash_lookup (name, shell_functions));
+}
+
+/* Find the function definition for the shell function named NAME. Returns
+ the entry or NULL. */
+FUNCTION_DEF *
+find_function_def (name)
+ const char *name;
+{
+#if defined (DEBUGGER)
+ return ((FUNCTION_DEF *)hash_lookup (name, shell_function_defs));
+#else
+ return ((FUNCTION_DEF *)0);
+#endif
+}
+
+/* Return the value of VAR. VAR is assumed to have been the result of a
+ lookup without any subscript, if arrays are compiled into the shell. */
+char *
+get_variable_value (var)
+ SHELL_VAR *var;
+{
+ if (var == 0)
+ return ((char *)NULL);
+#if defined (ARRAY_VARS)
+ else if (array_p (var))
+ return (array_reference (array_cell (var), 0));
+ else if (assoc_p (var))
+ return (assoc_reference (assoc_cell (var), "0"));
+#endif
+ else
+ return (value_cell (var));
+}
+
+/* Return the string value of a variable. Return NULL if the variable
+ doesn't exist. Don't cons a new string. This is a potential memory
+ leak if the variable is found in the temporary environment. Since
+ functions and variables have separate name spaces, returns NULL if
+ var_name is a shell function only. */
+char *
+get_string_value (var_name)
+ const char *var_name;
+{
+ SHELL_VAR *var;
+
+ var = find_variable (var_name);
+ return ((var) ? get_variable_value (var) : (char *)NULL);
+}
+
+/* This is present for use by the tilde and readline libraries. */
+char *
+sh_get_env_value (v)
+ const char *v;
+{
+ return get_string_value (v);
+}
+
+/* **************************************************************** */
+/* */
+/* Creating and setting variables */
+/* */
+/* **************************************************************** */
+
+/* Set NAME to VALUE if NAME has no value. */
+SHELL_VAR *
+set_if_not (name, value)
+ char *name, *value;
+{
+ SHELL_VAR *v;
+
+ if (shell_variables == 0)
+ create_variable_tables ();
+
+ v = find_variable (name);
+ if (v == 0)
+ v = bind_variable_internal (name, value, global_variables->table, HASH_NOSRCH, 0);
+ return (v);
+}
+
+/* Create a local variable referenced by NAME. */
+SHELL_VAR *
+make_local_variable (name)
+ const char *name;
+{
+ SHELL_VAR *new_var, *old_var;
+ VAR_CONTEXT *vc;
+ int was_tmpvar;
+ char *tmp_value;
+
+ /* local foo; local foo; is a no-op. */
+ old_var = find_variable (name);
+ if (old_var && local_p (old_var) && old_var->context == variable_context)
+ return (old_var);
+
+ was_tmpvar = old_var && tempvar_p (old_var);
+ /* If we're making a local variable in a shell function, the temporary env
+ has already been merged into the function's variable context stack. We
+ can assume that a temporary var in the same context appears in the same
+ VAR_CONTEXT and can safely be returned without creating a new variable
+ (which results in duplicate names in the same VAR_CONTEXT->table */
+ /* We can't just test tmpvar_p because variables in the temporary env given
+ to a shell function appear in the function's local variable VAR_CONTEXT
+ but retain their tempvar attribute. We want temporary variables that are
+ found in temporary_env, hence the test for last_table_searched, which is
+ set in hash_lookup and only (so far) checked here. */
+ if (was_tmpvar && old_var->context == variable_context && last_table_searched != temporary_env)
+ {
+ VUNSETATTR (old_var, att_invisible); /* XXX */
+ return (old_var);
+ }
+ if (was_tmpvar)
+ tmp_value = value_cell (old_var);
+
+ for (vc = shell_variables; vc; vc = vc->down)
+ if (vc_isfuncenv (vc) && vc->scope == variable_context)
+ break;
+
+ if (vc == 0)
+ {
+ internal_error (_("make_local_variable: no function context at current scope"));
+ return ((SHELL_VAR *)NULL);
+ }
+ else if (vc->table == 0)
+ vc->table = hash_create (TEMPENV_HASH_BUCKETS);
+
+ /* Since this is called only from the local/declare/typeset code, we can
+ call builtin_error here without worry (of course, it will also work
+ for anything that sets this_command_name). Variables with the `noassign'
+ attribute may not be made local. The test against old_var's context
+ level is to disallow local copies of readonly global variables (since I
+ believe that this could be a security hole). Readonly copies of calling
+ function local variables are OK. */
+ if (old_var && (noassign_p (old_var) ||
+ (readonly_p (old_var) && old_var->context == 0)))
+ {
+ if (readonly_p (old_var))
+ sh_readonly (name);
+ else if (noassign_p (old_var))
+ builtin_error (_("%s: variable may not be assigned value"), name);
+#if 0
+ /* Let noassign variables through with a warning */
+ if (readonly_p (old_var))
+#endif
+ return ((SHELL_VAR *)NULL);
+ }
+
+ if (old_var == 0)
+ new_var = make_new_variable (name, vc->table);
+ else
+ {
+ new_var = make_new_variable (name, vc->table);
+
+ /* If we found this variable in one of the temporary environments,
+ inherit its value. Watch to see if this causes problems with
+ things like `x=4 local x'. XXX - see above for temporary env
+ variables with the same context level as variable_context */
+ /* XXX - we should only do this if the variable is not an array. */
+ if (was_tmpvar)
+ var_setvalue (new_var, savestring (tmp_value));
+
+ new_var->attributes = exported_p (old_var) ? att_exported : 0;
+ }
+
+ vc->flags |= VC_HASLOCAL;
+
+ new_var->context = variable_context;
+ VSETATTR (new_var, att_local);
+
+ if (ifsname (name))
+ setifs (new_var);
+
+ if (was_tmpvar == 0 && no_invisible_vars == 0)
+ VSETATTR (new_var, att_invisible); /* XXX */
+ return (new_var);
+}
+
+/* Create a new shell variable with name NAME. */
+static SHELL_VAR *
+new_shell_variable (name)
+ const char *name;
+{
+ SHELL_VAR *entry;
+
+ entry = (SHELL_VAR *)xmalloc (sizeof (SHELL_VAR));
+
+ entry->name = savestring (name);
+ var_setvalue (entry, (char *)NULL);
+ CLEAR_EXPORTSTR (entry);
+
+ entry->dynamic_value = (sh_var_value_func_t *)NULL;
+ entry->assign_func = (sh_var_assign_func_t *)NULL;
+
+ entry->attributes = 0;
+
+ /* Always assume variables are to be made at toplevel!
+ make_local_variable has the responsibility of changing the
+ variable context. */
+ entry->context = 0;
+
+ return (entry);
+}
+
+/* Create a new shell variable with name NAME and add it to the hash table
+ TABLE. */
+static SHELL_VAR *
+make_new_variable (name, table)
+ const char *name;
+ HASH_TABLE *table;
+{
+ SHELL_VAR *entry;
+ BUCKET_CONTENTS *elt;
+
+ entry = new_shell_variable (name);
+
+ /* Make sure we have a shell_variables hash table to add to. */
+ if (shell_variables == 0)
+ create_variable_tables ();
+
+ elt = hash_insert (savestring (name), table, HASH_NOSRCH);
+ elt->data = (PTR_T)entry;
+
+ return entry;
+}
+
+#if defined (ARRAY_VARS)
+SHELL_VAR *
+make_new_array_variable (name)
+ char *name;
+{
+ SHELL_VAR *entry;
+ ARRAY *array;
+
+ entry = make_new_variable (name, global_variables->table);
+ array = array_create ();
+
+ var_setarray (entry, array);
+ VSETATTR (entry, att_array);
+ return entry;
+}
+
+SHELL_VAR *
+make_local_array_variable (name, assoc_ok)
+ char *name;
+ int assoc_ok;
+{
+ SHELL_VAR *var;
+ ARRAY *array;
+
+ var = make_local_variable (name);
+ if (var == 0 || array_p (var) || (assoc_ok && assoc_p (var)))
+ return var;
+
+ array = array_create ();
+
+ dispose_variable_value (var);
+ var_setarray (var, array);
+ VSETATTR (var, att_array);
+ return var;
+}
+
+SHELL_VAR *
+make_new_assoc_variable (name)
+ char *name;
+{
+ SHELL_VAR *entry;
+ HASH_TABLE *hash;
+
+ entry = make_new_variable (name, global_variables->table);
+ hash = assoc_create (0);
+
+ var_setassoc (entry, hash);
+ VSETATTR (entry, att_assoc);
+ return entry;
+}
+
+SHELL_VAR *
+make_local_assoc_variable (name)
+ char *name;
+{
+ SHELL_VAR *var;
+ HASH_TABLE *hash;
+
+ var = make_local_variable (name);
+ if (var == 0 || assoc_p (var))
+ return var;
+
+ dispose_variable_value (var);
+ hash = assoc_create (0);
+
+ var_setassoc (var, hash);
+ VSETATTR (var, att_assoc);
+ return var;
+}
+#endif
+
+char *
+make_variable_value (var, value, flags)
+ SHELL_VAR *var;
+ char *value;
+ int flags;
+{
+ char *retval, *oval;
+ intmax_t lval, rval;
+ int expok, olen, op;
+
+ /* If this variable has had its type set to integer (via `declare -i'),
+ then do expression evaluation on it and store the result. The
+ functions in expr.c (evalexp()) and bind_int_variable() are responsible
+ for turning off the integer flag if they don't want further
+ evaluation done. */
+ if (integer_p (var))
+ {
+ if (flags & ASS_APPEND)
+ {
+ oval = value_cell (var);
+ lval = evalexp (oval, &expok); /* ksh93 seems to do this */
+ if (expok == 0)
+ {
+ top_level_cleanup ();
+ jump_to_top_level (DISCARD);
+ }
+ }
+ rval = evalexp (value, &expok);
+ if (expok == 0)
+ {
+ top_level_cleanup ();
+ jump_to_top_level (DISCARD);
+ }
+ /* This can be fooled if the variable's value changes while evaluating
+ `rval'. We can change it if we move the evaluation of lval to here. */
+ if (flags & ASS_APPEND)
+ rval += lval;
+ retval = itos (rval);
+ }
+#if defined (CASEMOD_ATTRS)
+ else if (capcase_p (var) || uppercase_p (var) || lowercase_p (var))
+ {
+ if (flags & ASS_APPEND)
+ {
+ oval = get_variable_value (var);
+ if (oval == 0) /* paranoia */
+ oval = "";
+ olen = STRLEN (oval);
+ retval = (char *)xmalloc (olen + (value ? STRLEN (value) : 0) + 1);
+ strcpy (retval, oval);
+ if (value)
+ strcpy (retval+olen, value);
+ }
+ else if (*value)
+ retval = savestring (value);
+ else
+ {
+ retval = (char *)xmalloc (1);
+ retval[0] = '\0';
+ }
+ op = capcase_p (var) ? CASE_CAPITALIZE
+ : (uppercase_p (var) ? CASE_UPPER : CASE_LOWER);
+ oval = sh_modcase (retval, (char *)0, op);
+ free (retval);
+ retval = oval;
+ }
+#endif /* CASEMOD_ATTRS */
+ else if (value)
+ {
+ if (flags & ASS_APPEND)
+ {
+ oval = get_variable_value (var);
+ if (oval == 0) /* paranoia */
+ oval = "";
+ olen = STRLEN (oval);
+ retval = (char *)xmalloc (olen + (value ? STRLEN (value) : 0) + 1);
+ strcpy (retval, oval);
+ if (value)
+ strcpy (retval+olen, value);
+ }
+ else if (*value)
+ retval = savestring (value);
+ else
+ {
+ retval = (char *)xmalloc (1);
+ retval[0] = '\0';
+ }
+ }
+ else
+ retval = (char *)NULL;
+
+ return retval;
+}
+
+/* Bind a variable NAME to VALUE in the HASH_TABLE TABLE, which may be the
+ temporary environment (but usually is not). */
+static SHELL_VAR *
+bind_variable_internal (name, value, table, hflags, aflags)
+ const char *name;
+ char *value;
+ HASH_TABLE *table;
+ int hflags, aflags;
+{
+ char *newval;
+ SHELL_VAR *entry;
+
+ entry = (hflags & HASH_NOSRCH) ? (SHELL_VAR *)NULL : hash_lookup (name, table);
+ /* Follow the nameref chain here if this is the global variables table */
+ if (entry && nameref_p (entry) && (invisible_p (entry) == 0) && table == global_variables->table)
+ {
+ entry = find_global_variable (entry->name);
+ /* Let's see if we have a nameref referencing a variable that hasn't yet
+ been created. */
+ if (entry == 0)
+ entry = find_variable_last_nameref (name); /* XXX */
+ if (entry == 0) /* just in case */
+ return (entry);
+ }
+
+ /* The first clause handles `declare -n ref; ref=x;' */
+ if (entry && invisible_p (entry) && nameref_p (entry))
+ goto assign_value;
+ else if (entry && nameref_p (entry))
+ {
+ newval = nameref_cell (entry);
+#if defined (ARRAY_VARS)
+ /* declare -n foo=x[2] */
+ if (valid_array_reference (newval))
+ /* XXX - should it be aflags? */
+ entry = assign_array_element (newval, make_variable_value (entry, value, 0), aflags);
+ else
+#endif
+ {
+ entry = make_new_variable (newval, table);
+ var_setvalue (entry, make_variable_value (entry, value, 0));
+ }
+ }
+ else if (entry == 0)
+ {
+ entry = make_new_variable (name, table);
+ var_setvalue (entry, make_variable_value (entry, value, 0)); /* XXX */
+ }
+ else if (entry->assign_func) /* array vars have assign functions now */
+ {
+ INVALIDATE_EXPORTSTR (entry);
+ newval = (aflags & ASS_APPEND) ? make_variable_value (entry, value, aflags) : value;
+ if (assoc_p (entry))
+ entry = (*(entry->assign_func)) (entry, newval, -1, savestring ("0"));
+ else if (array_p (entry))
+ entry = (*(entry->assign_func)) (entry, newval, 0, 0);
+ else
+ entry = (*(entry->assign_func)) (entry, newval, -1, 0);
+ if (newval != value)
+ free (newval);
+ return (entry);
+ }
+ else
+ {
+assign_value:
+ if (readonly_p (entry) || noassign_p (entry))
+ {
+ if (readonly_p (entry))
+ err_readonly (name);
+ return (entry);
+ }
+
+ /* Variables which are bound are visible. */
+ VUNSETATTR (entry, att_invisible);
+
+#if defined (ARRAY_VARS)
+ if (assoc_p (entry) || array_p (entry))
+ newval = make_array_variable_value (entry, 0, "0", value, aflags);
+ else
+#endif
+
+ newval = make_variable_value (entry, value, aflags); /* XXX */
+
+ /* Invalidate any cached export string */
+ INVALIDATE_EXPORTSTR (entry);
+
+#if defined (ARRAY_VARS)
+ /* XXX -- this bears looking at again -- XXX */
+ /* If an existing array variable x is being assigned to with x=b or
+ `read x' or something of that nature, silently convert it to
+ x[0]=b or `read x[0]'. */
+ if (assoc_p (entry))
+ {
+ assoc_insert (assoc_cell (entry), savestring ("0"), newval);
+ free (newval);
+ }
+ else if (array_p (entry))
+ {
+ array_insert (array_cell (entry), 0, newval);
+ free (newval);
+ }
+ else
+#endif
+ {
+ FREE (value_cell (entry));
+ var_setvalue (entry, newval);
+ }
+ }
+
+ if (mark_modified_vars)
+ VSETATTR (entry, att_exported);
+
+ if (exported_p (entry))
+ array_needs_making = 1;
+
+ return (entry);
+}
+
+/* Bind a variable NAME to VALUE. This conses up the name
+ and value strings. If we have a temporary environment, we bind there
+ first, then we bind into shell_variables. */
+
+SHELL_VAR *
+bind_variable (name, value, flags)
+ const char *name;
+ char *value;
+ int flags;
+{
+ SHELL_VAR *v, *nv;
+ VAR_CONTEXT *vc, *nvc;
+ int level;
+ char *newname;
+
+ if (shell_variables == 0)
+ create_variable_tables ();
+
+ /* If we have a temporary environment, look there first for the variable,
+ and, if found, modify the value there before modifying it in the
+ shell_variables table. This allows sourced scripts to modify values
+ given to them in a temporary environment while modifying the variable
+ value that the caller sees. */
+ if (temporary_env)
+ bind_tempenv_variable (name, value);
+
+ /* XXX -- handle local variables here. */
+ for (vc = shell_variables; vc; vc = vc->down)
+ {
+ if (vc_isfuncenv (vc) || vc_isbltnenv (vc))
+ {
+ v = hash_lookup (name, vc->table);
+ nvc = vc;
+ if (v && nameref_p (v))
+ {
+ nv = find_variable_nameref_context (v, vc, &nvc);
+ if (nv == 0)
+ {
+ nv = find_variable_last_nameref_context (v, vc, &nvc);
+ if (nv && nameref_p (nv))
+ {
+ /* If this nameref variable doesn't have a value yet,
+ set the value. Otherwise, assign using the value as
+ normal. */
+ if (nameref_cell (nv) == 0)
+ return (bind_variable_internal (nv->name, value, nvc->table, 0, flags));
+#if defined (ARRAY_VARS)
+ else if (valid_array_reference (nameref_cell (nv)))
+ return (assign_array_element (nameref_cell (nv), value, flags));
+ else
+#endif
+ return (bind_variable_internal (nameref_cell (nv), value, nvc->table, 0, flags));
+ }
+ else
+ v = nv;
+ }
+ else
+ v = nv;
+ }
+ if (v)
+ return (bind_variable_internal (v->name, value, nvc->table, 0, flags));
+ }
+ }
+ /* bind_variable_internal will handle nameref resolution in this case */
+ return (bind_variable_internal (name, value, global_variables->table, 0, flags));
+}
+
+SHELL_VAR *
+bind_global_variable (name, value, flags)
+ const char *name;
+ char *value;
+ int flags;
+{
+ SHELL_VAR *v, *nv;
+ VAR_CONTEXT *vc, *nvc;
+ int level;
+
+ if (shell_variables == 0)
+ create_variable_tables ();
+
+ /* bind_variable_internal will handle nameref resolution in this case */
+ return (bind_variable_internal (name, value, global_variables->table, 0, flags));
+}
+
+/* Make VAR, a simple shell variable, have value VALUE. Once assigned a
+ value, variables are no longer invisible. This is a duplicate of part
+ of the internals of bind_variable. If the variable is exported, or
+ all modified variables should be exported, mark the variable for export
+ and note that the export environment needs to be recreated. */
+SHELL_VAR *
+bind_variable_value (var, value, aflags)
+ SHELL_VAR *var;
+ char *value;
+ int aflags;
+{
+ char *t;
+ int invis;
+
+ invis = invisible_p (var);
+ VUNSETATTR (var, att_invisible);
+
+ if (var->assign_func)
+ {
+ /* If we're appending, we need the old value, so use
+ make_variable_value */
+ t = (aflags & ASS_APPEND) ? make_variable_value (var, value, aflags) : value;
+ (*(var->assign_func)) (var, t, -1, 0);
+ if (t != value && t)
+ free (t);
+ }
+ else
+ {
+ t = make_variable_value (var, value, aflags);
+#if defined (ARRAY_VARS)
+ if ((aflags & ASS_NAMEREF) && (t == 0 || *t == 0 || (legal_identifier (t) == 0 && valid_array_reference (t) == 0)))
+#else
+ if ((aflags & ASS_NAMEREF) && (t == 0 || *t == 0 || legal_identifier (t) == 0))
+#endif
+ {
+ free (t);
+ if (invis)
+ VSETATTR (var, att_invisible); /* XXX */
+ return ((SHELL_VAR *)NULL);
+ }
+ FREE (value_cell (var));
+ var_setvalue (var, t);
+ }
+
+ INVALIDATE_EXPORTSTR (var);
+
+ if (mark_modified_vars)
+ VSETATTR (var, att_exported);
+
+ if (exported_p (var))
+ array_needs_making = 1;
+
+ return (var);
+}
+
+/* Bind/create a shell variable with the name LHS to the RHS.
+ This creates or modifies a variable such that it is an integer.
+
+ This used to be in expr.c, but it is here so that all of the
+ variable binding stuff is localized. Since we don't want any
+ recursive evaluation from bind_variable() (possible without this code,
+ since bind_variable() calls the evaluator for variables with the integer
+ attribute set), we temporarily turn off the integer attribute for each
+ variable we set here, then turn it back on after binding as necessary. */
+
+SHELL_VAR *
+bind_int_variable (lhs, rhs)
+ char *lhs, *rhs;
+{
+ register SHELL_VAR *v;
+ int isint, isarr, implicitarray;
+
+ isint = isarr = implicitarray = 0;
+#if defined (ARRAY_VARS)
+ if (valid_array_reference (lhs))
+ {
+ isarr = 1;
+ v = array_variable_part (lhs, (char **)0, (int *)0);
+ }
+ else
+#endif
+ v = find_variable (lhs);
+
+ if (v)
+ {
+ isint = integer_p (v);
+ VUNSETATTR (v, att_integer);
+#if defined (ARRAY_VARS)
+ if (array_p (v) && isarr == 0)
+ implicitarray = 1;
+#endif
+ }
+
+#if defined (ARRAY_VARS)
+ if (isarr)
+ v = assign_array_element (lhs, rhs, 0);
+ else if (implicitarray)
+ v = bind_array_variable (lhs, 0, rhs, 0);
+ else
+#endif
+ v = bind_variable (lhs, rhs, 0);
+
+ if (v && isint)
+ VSETATTR (v, att_integer);
+
+ VUNSETATTR (v, att_invisible);
+
+ return (v);
+}
+
+SHELL_VAR *
+bind_var_to_int (var, val)
+ char *var;
+ intmax_t val;
+{
+ char ibuf[INT_STRLEN_BOUND (intmax_t) + 1], *p;
+
+ p = fmtulong (val, 10, ibuf, sizeof (ibuf), 0);
+ return (bind_int_variable (var, p));
+}
+
+/* Do a function binding to a variable. You pass the name and
+ the command to bind to. This conses the name and command. */
+SHELL_VAR *
+bind_function (name, value)
+ const char *name;
+ COMMAND *value;
+{
+ SHELL_VAR *entry;
+
+ entry = find_function (name);
+ if (entry == 0)
+ {
+ BUCKET_CONTENTS *elt;
+
+ elt = hash_insert (savestring (name), shell_functions, HASH_NOSRCH);
+ entry = new_shell_variable (name);
+ elt->data = (PTR_T)entry;
+ }
+ else
+ INVALIDATE_EXPORTSTR (entry);
+
+ if (var_isset (entry))
+ dispose_command (function_cell (entry));
+
+ if (value)
+ var_setfunc (entry, copy_command (value));
+ else
+ var_setfunc (entry, 0);
+
+ VSETATTR (entry, att_function);
+
+ if (mark_modified_vars)
+ VSETATTR (entry, att_exported);
+
+ VUNSETATTR (entry, att_invisible); /* Just to be sure */
+
+ if (exported_p (entry))
+ array_needs_making = 1;
+
+#if defined (PROGRAMMABLE_COMPLETION)
+ set_itemlist_dirty (&it_functions);
+#endif
+
+ return (entry);
+}
+
+#if defined (DEBUGGER)
+/* Bind a function definition, which includes source file and line number
+ information in addition to the command, into the FUNCTION_DEF hash table.*/
+void
+bind_function_def (name, value)
+ const char *name;
+ FUNCTION_DEF *value;
+{
+ FUNCTION_DEF *entry;
+ BUCKET_CONTENTS *elt;
+ COMMAND *cmd;
+
+ entry = find_function_def (name);
+ if (entry)
+ {
+ dispose_function_def_contents (entry);
+ entry = copy_function_def_contents (value, entry);
+ }
+ else
+ {
+ cmd = value->command;
+ value->command = 0;
+ entry = copy_function_def (value);
+ value->command = cmd;
+
+ elt = hash_insert (savestring (name), shell_function_defs, HASH_NOSRCH);
+ elt->data = (PTR_T *)entry;
+ }
+}
+#endif /* DEBUGGER */
+
+/* Add STRING, which is of the form foo=bar, to the temporary environment
+ HASH_TABLE (temporary_env). The functions in execute_cmd.c are
+ responsible for moving the main temporary env to one of the other
+ temporary environments. The expansion code in subst.c calls this. */
+int
+assign_in_env (word, flags)
+ WORD_DESC *word;
+ int flags;
+{
+ int offset, aflags;
+ char *name, *temp, *value;
+ SHELL_VAR *var;
+ const char *string;
+
+ string = word->word;
+
+ aflags = 0;
+ offset = assignment (string, 0);
+ name = savestring (string);
+ value = (char *)NULL;
+
+ if (name[offset] == '=')
+ {
+ name[offset] = 0;
+
+ /* don't ignore the `+' when assigning temporary environment */
+ if (name[offset - 1] == '+')
+ {
+ name[offset - 1] = '\0';
+ aflags |= ASS_APPEND;
+ }
+
+ var = find_variable (name);
+ if (var && (readonly_p (var) || noassign_p (var)))
+ {
+ if (readonly_p (var))
+ err_readonly (name);
+ free (name);
+ return (0);
+ }
+
+ temp = name + offset + 1;
+ value = expand_assignment_string_to_string (temp, 0);
+
+ if (var && (aflags & ASS_APPEND))
+ {
+ temp = make_variable_value (var, value, aflags);
+ FREE (value);
+ value = temp;
+ }
+ }
+
+ if (temporary_env == 0)
+ temporary_env = hash_create (TEMPENV_HASH_BUCKETS);
+
+ var = hash_lookup (name, temporary_env);
+ if (var == 0)
+ var = make_new_variable (name, temporary_env);
+ else
+ FREE (value_cell (var));
+
+ if (value == 0)
+ {
+ value = (char *)xmalloc (1); /* like do_assignment_internal */
+ value[0] = '\0';
+ }
+
+ var_setvalue (var, value);
+ var->attributes |= (att_exported|att_tempvar);
+ var->context = variable_context; /* XXX */
+
+ INVALIDATE_EXPORTSTR (var);
+ var->exportstr = mk_env_string (name, value);
+
+ array_needs_making = 1;
+
+ if (flags)
+ stupidly_hack_special_variables (name);
+
+ if (echo_command_at_execute)
+ /* The Korn shell prints the `+ ' in front of assignment statements,
+ so we do too. */
+ xtrace_print_assignment (name, value, 0, 1);
+
+ free (name);
+ return 1;
+}
+
+/* **************************************************************** */
+/* */
+/* Copying variables */
+/* */
+/* **************************************************************** */
+
+#ifdef INCLUDE_UNUSED
+/* Copy VAR to a new data structure and return that structure. */
+SHELL_VAR *
+copy_variable (var)
+ SHELL_VAR *var;
+{
+ SHELL_VAR *copy = (SHELL_VAR *)NULL;
+
+ if (var)
+ {
+ copy = (SHELL_VAR *)xmalloc (sizeof (SHELL_VAR));
+
+ copy->attributes = var->attributes;
+ copy->name = savestring (var->name);
+
+ if (function_p (var))
+ var_setfunc (copy, copy_command (function_cell (var)));
+#if defined (ARRAY_VARS)
+ else if (array_p (var))
+ var_setarray (copy, array_copy (array_cell (var)));
+ else if (assoc_p (var))
+ var_setassoc (copy, assoc_copy (assoc_cell (var)));
+#endif
+ else if (nameref_cell (var)) /* XXX - nameref */
+ var_setref (copy, savestring (nameref_cell (var)));
+ else if (value_cell (var)) /* XXX - nameref */
+ var_setvalue (copy, savestring (value_cell (var)));
+ else
+ var_setvalue (copy, (char *)NULL);
+
+ copy->dynamic_value = var->dynamic_value;
+ copy->assign_func = var->assign_func;
+
+ copy->exportstr = COPY_EXPORTSTR (var);
+
+ copy->context = var->context;
+ }
+ return (copy);
+}
+#endif
+
+/* **************************************************************** */
+/* */
+/* Deleting and unsetting variables */
+/* */
+/* **************************************************************** */
+
+/* Dispose of the information attached to VAR. */
+static void
+dispose_variable_value (var)
+ SHELL_VAR *var;
+{
+ if (function_p (var))
+ dispose_command (function_cell (var));
+#if defined (ARRAY_VARS)
+ else if (array_p (var))
+ array_dispose (array_cell (var));
+ else if (assoc_p (var))
+ assoc_dispose (assoc_cell (var));
+#endif
+ else if (nameref_p (var))
+ FREE (nameref_cell (var));
+ else
+ FREE (value_cell (var));
+}
+
+void
+dispose_variable (var)
+ SHELL_VAR *var;
+{
+ if (var == 0)
+ return;
+
+ if (nofree_p (var) == 0)
+ dispose_variable_value (var);
+
+ FREE_EXPORTSTR (var);
+
+ free (var->name);
+
+ if (exported_p (var))
+ array_needs_making = 1;
+
+ free (var);
+}
+
+/* Unset the shell variable referenced by NAME. Unsetting a nameref variable
+ unsets the variable it resolves to but leaves the nameref alone. */
+int
+unbind_variable (name)
+ const char *name;
+{
+ SHELL_VAR *v, *nv;
+ int r;
+
+ v = var_lookup (name, shell_variables);
+ nv = (v && nameref_p (v)) ? find_variable_nameref (v) : (SHELL_VAR *)NULL;
+
+ r = nv ? makunbound (nv->name, shell_variables) : makunbound (name, shell_variables);
+ return r;
+}
+
+/* Unbind NAME, where NAME is assumed to be a nameref variable */
+int
+unbind_nameref (name)
+ const char *name;
+{
+ SHELL_VAR *v;
+
+ v = var_lookup (name, shell_variables);
+ if (v && nameref_p (v))
+ return makunbound (name, shell_variables);
+ return 0;
+}
+
+/* Unset the shell function named NAME. */
+int
+unbind_func (name)
+ const char *name;
+{
+ BUCKET_CONTENTS *elt;
+ SHELL_VAR *func;
+
+ elt = hash_remove (name, shell_functions, 0);
+
+ if (elt == 0)
+ return -1;
+
+#if defined (PROGRAMMABLE_COMPLETION)
+ set_itemlist_dirty (&it_functions);
+#endif
+
+ func = (SHELL_VAR *)elt->data;
+ if (func)
+ {
+ if (exported_p (func))
+ array_needs_making++;
+ dispose_variable (func);
+ }
+
+ free (elt->key);
+ free (elt);
+
+ return 0;
+}
+
+#if defined (DEBUGGER)
+int
+unbind_function_def (name)
+ const char *name;
+{
+ BUCKET_CONTENTS *elt;
+ FUNCTION_DEF *funcdef;
+
+ elt = hash_remove (name, shell_function_defs, 0);
+
+ if (elt == 0)
+ return -1;
+
+ funcdef = (FUNCTION_DEF *)elt->data;
+ if (funcdef)
+ dispose_function_def (funcdef);
+
+ free (elt->key);
+ free (elt);
+
+ return 0;
+}
+#endif /* DEBUGGER */
+
+int
+delete_var (name, vc)
+ const char *name;
+ VAR_CONTEXT *vc;
+{
+ BUCKET_CONTENTS *elt;
+ SHELL_VAR *old_var;
+ VAR_CONTEXT *v;
+
+ for (elt = (BUCKET_CONTENTS *)NULL, v = vc; v; v = v->down)
+ if (elt = hash_remove (name, v->table, 0))
+ break;
+
+ if (elt == 0)
+ return (-1);
+
+ old_var = (SHELL_VAR *)elt->data;
+ free (elt->key);
+ free (elt);
+
+ dispose_variable (old_var);
+ return (0);
+}
+
+/* Make the variable associated with NAME go away. HASH_LIST is the
+ hash table from which this variable should be deleted (either
+ shell_variables or shell_functions).
+ Returns non-zero if the variable couldn't be found. */
+int
+makunbound (name, vc)
+ const char *name;
+ VAR_CONTEXT *vc;
+{
+ BUCKET_CONTENTS *elt, *new_elt;
+ SHELL_VAR *old_var;
+ VAR_CONTEXT *v;
+ char *t;
+
+ for (elt = (BUCKET_CONTENTS *)NULL, v = vc; v; v = v->down)
+ if (elt = hash_remove (name, v->table, 0))
+ break;
+
+ if (elt == 0)
+ return (-1);
+
+ old_var = (SHELL_VAR *)elt->data;
+
+ if (old_var && exported_p (old_var))
+ array_needs_making++;
+
+ /* If we're unsetting a local variable and we're still executing inside
+ the function, just mark the variable as invisible. The function
+ eventually called by pop_var_context() will clean it up later. This
+ must be done so that if the variable is subsequently assigned a new
+ value inside the function, the `local' attribute is still present.
+ We also need to add it back into the correct hash table. */
+ if (old_var && local_p (old_var) && variable_context == old_var->context)
+ {
+ if (nofree_p (old_var))
+ var_setvalue (old_var, (char *)NULL);
+#if defined (ARRAY_VARS)
+ else if (array_p (old_var))
+ array_dispose (array_cell (old_var));
+ else if (assoc_p (old_var))
+ assoc_dispose (assoc_cell (old_var));
+#endif
+ else if (nameref_p (old_var))
+ FREE (nameref_cell (old_var));
+ else
+ FREE (value_cell (old_var));
+ /* Reset the attributes. Preserve the export attribute if the variable
+ came from a temporary environment. Make sure it stays local, and
+ make it invisible. */
+ old_var->attributes = (exported_p (old_var) && tempvar_p (old_var)) ? att_exported : 0;
+ VSETATTR (old_var, att_local);
+ VSETATTR (old_var, att_invisible);
+ var_setvalue (old_var, (char *)NULL);
+ INVALIDATE_EXPORTSTR (old_var);
+
+ new_elt = hash_insert (savestring (old_var->name), v->table, 0);
+ new_elt->data = (PTR_T)old_var;
+ stupidly_hack_special_variables (old_var->name);
+
+ free (elt->key);
+ free (elt);
+ return (0);
+ }
+
+ /* Have to save a copy of name here, because it might refer to
+ old_var->name. If so, stupidly_hack_special_variables will
+ reference freed memory. */
+ t = savestring (name);
+
+ free (elt->key);
+ free (elt);
+
+ dispose_variable (old_var);
+ stupidly_hack_special_variables (t);
+ free (t);
+
+ return (0);
+}
+
+/* Get rid of all of the variables in the current context. */
+void
+kill_all_local_variables ()
+{
+ VAR_CONTEXT *vc;
+
+ for (vc = shell_variables; vc; vc = vc->down)
+ if (vc_isfuncenv (vc) && vc->scope == variable_context)
+ break;
+ if (vc == 0)
+ return; /* XXX */
+
+ if (vc->table && vc_haslocals (vc))
+ {
+ delete_all_variables (vc->table);
+ hash_dispose (vc->table);
+ }
+ vc->table = (HASH_TABLE *)NULL;
+}
+
+static void
+free_variable_hash_data (data)
+ PTR_T data;
+{
+ SHELL_VAR *var;
+
+ var = (SHELL_VAR *)data;
+ dispose_variable (var);
+}
+
+/* Delete the entire contents of the hash table. */
+void
+delete_all_variables (hashed_vars)
+ HASH_TABLE *hashed_vars;
+{
+ hash_flush (hashed_vars, free_variable_hash_data);
+}
+
+/* **************************************************************** */
+/* */
+/* Setting variable attributes */
+/* */
+/* **************************************************************** */
+
+#define FIND_OR_MAKE_VARIABLE(name, entry) \
+ do \
+ { \
+ entry = find_variable (name); \
+ if (!entry) \
+ { \
+ entry = bind_variable (name, "", 0); \
+ if (!no_invisible_vars && entry) entry->attributes |= att_invisible; \
+ } \
+ } \
+ while (0)
+
+/* Make the variable associated with NAME be readonly.
+ If NAME does not exist yet, create it. */
+void
+set_var_read_only (name)
+ char *name;
+{
+ SHELL_VAR *entry;
+
+ FIND_OR_MAKE_VARIABLE (name, entry);
+ VSETATTR (entry, att_readonly);
+}
+
+#ifdef INCLUDE_UNUSED
+/* Make the function associated with NAME be readonly.
+ If NAME does not exist, we just punt, like auto_export code below. */
+void
+set_func_read_only (name)
+ const char *name;
+{
+ SHELL_VAR *entry;
+
+ entry = find_function (name);
+ if (entry)
+ VSETATTR (entry, att_readonly);
+}
+
+/* Make the variable associated with NAME be auto-exported.
+ If NAME does not exist yet, create it. */
+void
+set_var_auto_export (name)
+ char *name;
+{
+ SHELL_VAR *entry;
+
+ FIND_OR_MAKE_VARIABLE (name, entry);
+ set_auto_export (entry);
+}
+
+/* Make the function associated with NAME be auto-exported. */
+void
+set_func_auto_export (name)
+ const char *name;
+{
+ SHELL_VAR *entry;
+
+ entry = find_function (name);
+ if (entry)
+ set_auto_export (entry);
+}
+#endif
+
+/* **************************************************************** */
+/* */
+/* Creating lists of variables */
+/* */
+/* **************************************************************** */
+
+static VARLIST *
+vlist_alloc (nentries)
+ int nentries;
+{
+ VARLIST *vlist;
+
+ vlist = (VARLIST *)xmalloc (sizeof (VARLIST));
+ vlist->list = (SHELL_VAR **)xmalloc ((nentries + 1) * sizeof (SHELL_VAR *));
+ vlist->list_size = nentries;
+ vlist->list_len = 0;
+ vlist->list[0] = (SHELL_VAR *)NULL;
+
+ return vlist;
+}
+
+static VARLIST *
+vlist_realloc (vlist, n)
+ VARLIST *vlist;
+ int n;
+{
+ if (vlist == 0)
+ return (vlist = vlist_alloc (n));
+ if (n > vlist->list_size)
+ {
+ vlist->list_size = n;
+ vlist->list = (SHELL_VAR **)xrealloc (vlist->list, (vlist->list_size + 1) * sizeof (SHELL_VAR *));
+ }
+ return vlist;
+}
+
+static void
+vlist_add (vlist, var, flags)
+ VARLIST *vlist;
+ SHELL_VAR *var;
+ int flags;
+{
+ register int i;
+
+ for (i = 0; i < vlist->list_len; i++)
+ if (STREQ (var->name, vlist->list[i]->name))
+ break;
+ if (i < vlist->list_len)
+ return;
+
+ if (i >= vlist->list_size)
+ vlist = vlist_realloc (vlist, vlist->list_size + 16);
+
+ vlist->list[vlist->list_len++] = var;
+ vlist->list[vlist->list_len] = (SHELL_VAR *)NULL;
+}
+
+/* Map FUNCTION over the variables in VAR_HASH_TABLE. Return an array of the
+ variables for which FUNCTION returns a non-zero value. A NULL value
+ for FUNCTION means to use all variables. */
+SHELL_VAR **
+map_over (function, vc)
+ sh_var_map_func_t *function;
+ VAR_CONTEXT *vc;
+{
+ VAR_CONTEXT *v;
+ VARLIST *vlist;
+ SHELL_VAR **ret;
+ int nentries;
+
+ for (nentries = 0, v = vc; v; v = v->down)
+ nentries += HASH_ENTRIES (v->table);
+
+ if (nentries == 0)
+ return (SHELL_VAR **)NULL;
+
+ vlist = vlist_alloc (nentries);
+
+ for (v = vc; v; v = v->down)
+ flatten (v->table, function, vlist, 0);
+
+ ret = vlist->list;
+ free (vlist);
+ return ret;
+}
+
+SHELL_VAR **
+map_over_funcs (function)
+ sh_var_map_func_t *function;
+{
+ VARLIST *vlist;
+ SHELL_VAR **ret;
+
+ if (shell_functions == 0 || HASH_ENTRIES (shell_functions) == 0)
+ return ((SHELL_VAR **)NULL);
+
+ vlist = vlist_alloc (HASH_ENTRIES (shell_functions));
+
+ flatten (shell_functions, function, vlist, 0);
+
+ ret = vlist->list;
+ free (vlist);
+ return ret;
+}
+
+/* Flatten VAR_HASH_TABLE, applying FUNC to each member and adding those
+ elements for which FUNC succeeds to VLIST->list. FLAGS is reserved
+ for future use. Only unique names are added to VLIST. If FUNC is
+ NULL, each variable in VAR_HASH_TABLE is added to VLIST. If VLIST is
+ NULL, FUNC is applied to each SHELL_VAR in VAR_HASH_TABLE. If VLIST
+ and FUNC are both NULL, nothing happens. */
+static void
+flatten (var_hash_table, func, vlist, flags)
+ HASH_TABLE *var_hash_table;
+ sh_var_map_func_t *func;
+ VARLIST *vlist;
+ int flags;
+{
+ register int i;
+ register BUCKET_CONTENTS *tlist;
+ int r;
+ SHELL_VAR *var;
+
+ if (var_hash_table == 0 || (HASH_ENTRIES (var_hash_table) == 0) || (vlist == 0 && func == 0))
+ return;
+
+ for (i = 0; i < var_hash_table->nbuckets; i++)
+ {
+ for (tlist = hash_items (i, var_hash_table); tlist; tlist = tlist->next)
+ {
+ var = (SHELL_VAR *)tlist->data;
+
+ r = func ? (*func) (var) : 1;
+ if (r && vlist)
+ vlist_add (vlist, var, flags);
+ }
+ }
+}
+
+void
+sort_variables (array)
+ SHELL_VAR **array;
+{
+ qsort (array, strvec_len ((char **)array), sizeof (SHELL_VAR *), (QSFUNC *)qsort_var_comp);
+}
+
+static int
+qsort_var_comp (var1, var2)
+ SHELL_VAR **var1, **var2;
+{
+ int result;
+
+ if ((result = (*var1)->name[0] - (*var2)->name[0]) == 0)
+ result = strcmp ((*var1)->name, (*var2)->name);
+
+ return (result);
+}
+
+/* Apply FUNC to each variable in SHELL_VARIABLES, adding each one for
+ which FUNC succeeds to an array of SHELL_VAR *s. Returns the array. */
+static SHELL_VAR **
+vapply (func)
+ sh_var_map_func_t *func;
+{
+ SHELL_VAR **list;
+
+ list = map_over (func, shell_variables);
+ if (list /* && posixly_correct */)
+ sort_variables (list);
+ return (list);
+}
+
+/* Apply FUNC to each variable in SHELL_FUNCTIONS, adding each one for
+ which FUNC succeeds to an array of SHELL_VAR *s. Returns the array. */
+static SHELL_VAR **
+fapply (func)
+ sh_var_map_func_t *func;
+{
+ SHELL_VAR **list;
+
+ list = map_over_funcs (func);
+ if (list /* && posixly_correct */)
+ sort_variables (list);
+ return (list);
+}
+
+/* Create a NULL terminated array of all the shell variables. */
+SHELL_VAR **
+all_shell_variables ()
+{
+ return (vapply ((sh_var_map_func_t *)NULL));
+}
+
+/* Create a NULL terminated array of all the shell functions. */
+SHELL_VAR **
+all_shell_functions ()
+{
+ return (fapply ((sh_var_map_func_t *)NULL));
+}
+
+static int
+visible_var (var)
+ SHELL_VAR *var;
+{
+ return (invisible_p (var) == 0);
+}
+
+SHELL_VAR **
+all_visible_functions ()
+{
+ return (fapply (visible_var));
+}
+
+SHELL_VAR **
+all_visible_variables ()
+{
+ return (vapply (visible_var));
+}
+
+/* Return non-zero if the variable VAR is visible and exported. Array
+ variables cannot be exported. */
+static int
+visible_and_exported (var)
+ SHELL_VAR *var;
+{
+ return (invisible_p (var) == 0 && exported_p (var));
+}
+
+/* Candidate variables for the export environment are either valid variables
+ with the export attribute or invalid variables inherited from the initial
+ environment and simply passed through. */
+static int
+export_environment_candidate (var)
+ SHELL_VAR *var;
+{
+ return (exported_p (var) && (invisible_p (var) == 0 || imported_p (var)));
+}
+
+/* Return non-zero if VAR is a local variable in the current context and
+ is exported. */
+static int
+local_and_exported (var)
+ SHELL_VAR *var;
+{
+ return (invisible_p (var) == 0 && local_p (var) && var->context == variable_context && exported_p (var));
+}
+
+SHELL_VAR **
+all_exported_variables ()
+{
+ return (vapply (visible_and_exported));
+}
+
+SHELL_VAR **
+local_exported_variables ()
+{
+ return (vapply (local_and_exported));
+}
+
+static int
+variable_in_context (var)
+ SHELL_VAR *var;
+{
+ return (invisible_p (var) == 0 && local_p (var) && var->context == variable_context);
+}
+
+SHELL_VAR **
+all_local_variables ()
+{
+ VARLIST *vlist;
+ SHELL_VAR **ret;
+ VAR_CONTEXT *vc;
+
+ vc = shell_variables;
+ for (vc = shell_variables; vc; vc = vc->down)
+ if (vc_isfuncenv (vc) && vc->scope == variable_context)
+ break;
+
+ if (vc == 0)
+ {
+ internal_error (_("all_local_variables: no function context at current scope"));
+ return (SHELL_VAR **)NULL;
+ }
+ if (vc->table == 0 || HASH_ENTRIES (vc->table) == 0 || vc_haslocals (vc) == 0)
+ return (SHELL_VAR **)NULL;
+
+ vlist = vlist_alloc (HASH_ENTRIES (vc->table));
+
+ flatten (vc->table, variable_in_context, vlist, 0);
+
+ ret = vlist->list;
+ free (vlist);
+ if (ret)
+ sort_variables (ret);
+ return ret;
+}
+
+#if defined (ARRAY_VARS)
+/* Return non-zero if the variable VAR is visible and an array. */
+static int
+visible_array_vars (var)
+ SHELL_VAR *var;
+{
+ return (invisible_p (var) == 0 && array_p (var));
+}
+
+SHELL_VAR **
+all_array_variables ()
+{
+ return (vapply (visible_array_vars));
+}
+#endif /* ARRAY_VARS */
+
+char **
+all_variables_matching_prefix (prefix)
+ const char *prefix;
+{
+ SHELL_VAR **varlist;
+ char **rlist;
+ int vind, rind, plen;
+
+ plen = STRLEN (prefix);
+ varlist = all_visible_variables ();
+ for (vind = 0; varlist && varlist[vind]; vind++)
+ ;
+ if (varlist == 0 || vind == 0)
+ return ((char **)NULL);
+ rlist = strvec_create (vind + 1);
+ for (vind = rind = 0; varlist[vind]; vind++)
+ {
+ if (plen == 0 || STREQN (prefix, varlist[vind]->name, plen))
+ rlist[rind++] = savestring (varlist[vind]->name);
+ }
+ rlist[rind] = (char *)0;
+ free (varlist);
+
+ return rlist;
+}
+
+/* **************************************************************** */
+/* */
+/* Managing temporary variable scopes */
+/* */
+/* **************************************************************** */
+
+/* Make variable NAME have VALUE in the temporary environment. */
+static SHELL_VAR *
+bind_tempenv_variable (name, value)
+ const char *name;
+ char *value;
+{
+ SHELL_VAR *var;
+
+ var = temporary_env ? hash_lookup (name, temporary_env) : (SHELL_VAR *)NULL;
+
+ if (var)
+ {
+ FREE (value_cell (var));
+ var_setvalue (var, savestring (value));
+ INVALIDATE_EXPORTSTR (var);
+ }
+
+ return (var);
+}
+
+/* Find a variable in the temporary environment that is named NAME.
+ Return the SHELL_VAR *, or NULL if not found. */
+SHELL_VAR *
+find_tempenv_variable (name)
+ const char *name;
+{
+ return (temporary_env ? hash_lookup (name, temporary_env) : (SHELL_VAR *)NULL);
+}
+
+char **tempvar_list;
+int tvlist_ind;
+
+/* Push the variable described by (SHELL_VAR *)DATA down to the next
+ variable context from the temporary environment. */
+static void
+push_temp_var (data)
+ PTR_T data;
+{
+ SHELL_VAR *var, *v;
+ HASH_TABLE *binding_table;
+
+ var = (SHELL_VAR *)data;
+
+ binding_table = shell_variables->table;
+ if (binding_table == 0)
+ {
+ if (shell_variables == global_variables)
+ /* shouldn't happen */
+ binding_table = shell_variables->table = global_variables->table = hash_create (0);
+ else
+ binding_table = shell_variables->table = hash_create (TEMPENV_HASH_BUCKETS);
+ }
+
+ v = bind_variable_internal (var->name, value_cell (var), binding_table, 0, 0);
+
+ /* XXX - should we set the context here? It shouldn't matter because of how
+ assign_in_env works, but might want to check. */
+ if (binding_table == global_variables->table) /* XXX */
+ var->attributes &= ~(att_tempvar|att_propagate);
+ else
+ {
+ var->attributes |= att_propagate;
+ if (binding_table == shell_variables->table)
+ shell_variables->flags |= VC_HASTMPVAR;
+ }
+ v->attributes |= var->attributes;
+
+ if (find_special_var (var->name) >= 0)
+ tempvar_list[tvlist_ind++] = savestring (var->name);
+
+ dispose_variable (var);
+}
+
+static void
+propagate_temp_var (data)
+ PTR_T data;
+{
+ SHELL_VAR *var;
+
+ var = (SHELL_VAR *)data;
+ if (tempvar_p (var) && (var->attributes & att_propagate))
+ push_temp_var (data);
+ else
+ {
+ if (find_special_var (var->name) >= 0)
+ tempvar_list[tvlist_ind++] = savestring (var->name);
+ dispose_variable (var);
+ }
+}
+
+/* Free the storage used in the hash table for temporary
+ environment variables. PUSHF is a function to be called
+ to free each hash table entry. It takes care of pushing variables
+ to previous scopes if appropriate. PUSHF stores names of variables
+ that require special handling (e.g., IFS) on tempvar_list, so this
+ function can call stupidly_hack_special_variables on all the
+ variables in the list when the temporary hash table is destroyed. */
+static void
+dispose_temporary_env (pushf)
+ sh_free_func_t *pushf;
+{
+ int i;
+
+ tempvar_list = strvec_create (HASH_ENTRIES (temporary_env) + 1);
+ tempvar_list[tvlist_ind = 0] = 0;
+
+ hash_flush (temporary_env, pushf);
+ hash_dispose (temporary_env);
+ temporary_env = (HASH_TABLE *)NULL;
+
+ tempvar_list[tvlist_ind] = 0;
+
+ array_needs_making = 1;
+
+#if 0
+ sv_ifs ("IFS"); /* XXX here for now -- check setifs in assign_in_env */
+#endif
+ for (i = 0; i < tvlist_ind; i++)
+ stupidly_hack_special_variables (tempvar_list[i]);
+
+ strvec_dispose (tempvar_list);
+ tempvar_list = 0;
+ tvlist_ind = 0;
+}
+
+void
+dispose_used_env_vars ()
+{
+ if (temporary_env)
+ {
+ dispose_temporary_env (propagate_temp_var);
+ maybe_make_export_env ();
+ }
+}
+
+/* Take all of the shell variables in the temporary environment HASH_TABLE
+ and make shell variables from them at the current variable context. */
+void
+merge_temporary_env ()
+{
+ if (temporary_env)
+ dispose_temporary_env (push_temp_var);
+}
+
+/* **************************************************************** */
+/* */
+/* Creating and manipulating the environment */
+/* */
+/* **************************************************************** */
+
+static inline char *
+mk_env_string (name, value)
+ const char *name, *value;
+{
+ int name_len, value_len;
+ char *p;
+
+ name_len = strlen (name);
+ value_len = STRLEN (value);
+ p = (char *)xmalloc (2 + name_len + value_len);
+ strcpy (p, name);
+ p[name_len] = '=';
+ if (value && *value)
+ strcpy (p + name_len + 1, value);
+ else
+ p[name_len + 1] = '\0';
+ return (p);
+}
+
+#ifdef DEBUG
+/* Debugging */
+static int
+valid_exportstr (v)
+ SHELL_VAR *v;
+{
+ char *s;
+
+ s = v->exportstr;
+ if (s == 0)
+ {
+ internal_error (_("%s has null exportstr"), v->name);
+ return (0);
+ }
+ if (legal_variable_starter ((unsigned char)*s) == 0)
+ {
+ internal_error (_("invalid character %d in exportstr for %s"), *s, v->name);
+ return (0);
+ }
+ for (s = v->exportstr + 1; s && *s; s++)
+ {
+ if (*s == '=')
+ break;
+ if (legal_variable_char ((unsigned char)*s) == 0)
+ {
+ internal_error (_("invalid character %d in exportstr for %s"), *s, v->name);
+ return (0);
+ }
+ }
+ if (*s != '=')
+ {
+ internal_error (_("no `=' in exportstr for %s"), v->name);
+ return (0);
+ }
+ return (1);
+}
+#endif
+
+static char **
+make_env_array_from_var_list (vars)
+ SHELL_VAR **vars;
+{
+ register int i, list_index;
+ register SHELL_VAR *var;
+ char **list, *value;
+
+ list = strvec_create ((1 + strvec_len ((char **)vars)));
+
+#define USE_EXPORTSTR (value == var->exportstr)
+
+ for (i = 0, list_index = 0; var = vars[i]; i++)
+ {
+#if defined (__CYGWIN__)
+ /* We don't use the exportstr stuff on Cygwin at all. */
+ INVALIDATE_EXPORTSTR (var);
+#endif
+ if (var->exportstr)
+ value = var->exportstr;
+ else if (function_p (var))
+ value = named_function_string ((char *)NULL, function_cell (var), 0);
+#if defined (ARRAY_VARS)
+ else if (array_p (var))
+# if ARRAY_EXPORT
+ value = array_to_assignment_string (array_cell (var));
+# else
+ continue; /* XXX array vars cannot yet be exported */
+# endif /* ARRAY_EXPORT */
+ else if (assoc_p (var))
+# if 0
+ value = assoc_to_assignment_string (assoc_cell (var));
+# else
+ continue; /* XXX associative array vars cannot yet be exported */
+# endif
+#endif
+ else
+ value = value_cell (var);
+
+ if (value)
+ {
+ /* Gee, I'd like to get away with not using savestring() if we're
+ using the cached exportstr... */
+ list[list_index] = USE_EXPORTSTR ? savestring (value)
+ : mk_env_string (var->name, value);
+
+ if (USE_EXPORTSTR == 0)
+ SAVE_EXPORTSTR (var, list[list_index]);
+
+ list_index++;
+#undef USE_EXPORTSTR
+
+#if 0 /* not yet */
+#if defined (ARRAY_VARS)
+ if (array_p (var) || assoc_p (var))
+ free (value);
+#endif
+#endif
+ }
+ }
+
+ list[list_index] = (char *)NULL;
+ return (list);
+}
+
+/* Make an array of assignment statements from the hash table
+ HASHED_VARS which contains SHELL_VARs. Only visible, exported
+ variables are eligible. */
+static char **
+make_var_export_array (vcxt)
+ VAR_CONTEXT *vcxt;
+{
+ char **list;
+ SHELL_VAR **vars;
+
+#if 0
+ vars = map_over (visible_and_exported, vcxt);
+#else
+ vars = map_over (export_environment_candidate, vcxt);
+#endif
+
+ if (vars == 0)
+ return (char **)NULL;
+
+ list = make_env_array_from_var_list (vars);
+
+ free (vars);
+ return (list);
+}
+
+static char **
+make_func_export_array ()
+{
+ char **list;
+ SHELL_VAR **vars;
+
+ vars = map_over_funcs (visible_and_exported);
+ if (vars == 0)
+ return (char **)NULL;
+
+ list = make_env_array_from_var_list (vars);
+
+ free (vars);
+ return (list);
+}
+
+/* Add ENVSTR to the end of the exported environment, EXPORT_ENV. */
+#define add_to_export_env(envstr,do_alloc) \
+do \
+ { \
+ if (export_env_index >= (export_env_size - 1)) \
+ { \
+ export_env_size += 16; \
+ export_env = strvec_resize (export_env, export_env_size); \
+ environ = export_env; \
+ } \
+ export_env[export_env_index++] = (do_alloc) ? savestring (envstr) : envstr; \
+ export_env[export_env_index] = (char *)NULL; \
+ } while (0)
+
+/* Add ASSIGN to EXPORT_ENV, or supercede a previous assignment in the
+ array with the same left-hand side. Return the new EXPORT_ENV. */
+char **
+add_or_supercede_exported_var (assign, do_alloc)
+ char *assign;
+ int do_alloc;
+{
+ register int i;
+ int equal_offset;
+
+ equal_offset = assignment (assign, 0);
+ if (equal_offset == 0)
+ return (export_env);
+
+ /* If this is a function, then only supersede the function definition.
+ We do this by including the `=() {' in the comparison, like
+ initialize_shell_variables does. */
+ if (assign[equal_offset + 1] == '(' &&
+ strncmp (assign + equal_offset + 2, ") {", 3) == 0) /* } */
+ equal_offset += 4;
+
+ for (i = 0; i < export_env_index; i++)
+ {
+ if (STREQN (assign, export_env[i], equal_offset + 1))
+ {
+ free (export_env[i]);
+ export_env[i] = do_alloc ? savestring (assign) : assign;
+ return (export_env);
+ }
+ }
+ add_to_export_env (assign, do_alloc);
+ return (export_env);
+}
+
+static void
+add_temp_array_to_env (temp_array, do_alloc, do_supercede)
+ char **temp_array;
+ int do_alloc, do_supercede;
+{
+ register int i;
+
+ if (temp_array == 0)
+ return;
+
+ for (i = 0; temp_array[i]; i++)
+ {
+ if (do_supercede)
+ export_env = add_or_supercede_exported_var (temp_array[i], do_alloc);
+ else
+ add_to_export_env (temp_array[i], do_alloc);
+ }
+
+ free (temp_array);
+}
+
+/* Make the environment array for the command about to be executed, if the
+ array needs making. Otherwise, do nothing. If a shell action could
+ change the array that commands receive for their environment, then the
+ code should `array_needs_making++'.
+
+ The order to add to the array is:
+ temporary_env
+ list of var contexts whose head is shell_variables
+ shell_functions
+
+ This is the shell variable lookup order. We add only new variable
+ names at each step, which allows local variables and variables in
+ the temporary environments to shadow variables in the global (or
+ any previous) scope.
+*/
+
+static int
+n_shell_variables ()
+{
+ VAR_CONTEXT *vc;
+ int n;
+
+ for (n = 0, vc = shell_variables; vc; vc = vc->down)
+ n += HASH_ENTRIES (vc->table);
+ return n;
+}
+
+int
+chkexport (name)
+ char *name;
+{
+ SHELL_VAR *v;
+
+ v = find_variable (name);
+ if (v && exported_p (v))
+ {
+ array_needs_making = 1;
+ maybe_make_export_env ();
+ return 1;
+ }
+ return 0;
+}
+
+void
+maybe_make_export_env ()
+{
+ register char **temp_array;
+ int new_size;
+ VAR_CONTEXT *tcxt;
+
+ if (array_needs_making)
+ {
+ if (export_env)
+ strvec_flush (export_env);
+
+ /* Make a guess based on how many shell variables and functions we
+ have. Since there will always be array variables, and array
+ variables are not (yet) exported, this will always be big enough
+ for the exported variables and functions. */
+ new_size = n_shell_variables () + HASH_ENTRIES (shell_functions) + 1 +
+ HASH_ENTRIES (temporary_env);
+ if (new_size > export_env_size)
+ {
+ export_env_size = new_size;
+ export_env = strvec_resize (export_env, export_env_size);
+ environ = export_env;
+ }
+ export_env[export_env_index = 0] = (char *)NULL;
+
+ /* Make a dummy variable context from the temporary_env, stick it on
+ the front of shell_variables, call make_var_export_array on the
+ whole thing to flatten it, and convert the list of SHELL_VAR *s
+ to the form needed by the environment. */
+ if (temporary_env)
+ {
+ tcxt = new_var_context ((char *)NULL, 0);
+ tcxt->table = temporary_env;
+ tcxt->down = shell_variables;
+ }
+ else
+ tcxt = shell_variables;
+
+ temp_array = make_var_export_array (tcxt);
+ if (temp_array)
+ add_temp_array_to_env (temp_array, 0, 0);
+
+ if (tcxt != shell_variables)
+ free (tcxt);
+
+#if defined (RESTRICTED_SHELL)
+ /* Restricted shells may not export shell functions. */
+ temp_array = restricted ? (char **)0 : make_func_export_array ();
+#else
+ temp_array = make_func_export_array ();
+#endif
+ if (temp_array)
+ add_temp_array_to_env (temp_array, 0, 0);
+
+ array_needs_making = 0;
+ }
+}
+
+/* This is an efficiency hack. PWD and OLDPWD are auto-exported, so
+ we will need to remake the exported environment every time we
+ change directories. `_' is always put into the environment for
+ every external command, so without special treatment it will always
+ cause the environment to be remade.
+
+ If there is no other reason to make the exported environment, we can
+ just update the variables in place and mark the exported environment
+ as no longer needing a remake. */
+void
+update_export_env_inplace (env_prefix, preflen, value)
+ char *env_prefix;
+ int preflen;
+ char *value;
+{
+ char *evar;
+
+ evar = (char *)xmalloc (STRLEN (value) + preflen + 1);
+ strcpy (evar, env_prefix);
+ if (value)
+ strcpy (evar + preflen, value);
+ export_env = add_or_supercede_exported_var (evar, 0);
+}
+
+/* We always put _ in the environment as the name of this command. */
+void
+put_command_name_into_env (command_name)
+ char *command_name;
+{
+ update_export_env_inplace ("_=", 2, command_name);
+}
+
+/* **************************************************************** */
+/* */
+/* Managing variable contexts */
+/* */
+/* **************************************************************** */
+
+/* Allocate and return a new variable context with NAME and FLAGS.
+ NAME can be NULL. */
+
+VAR_CONTEXT *
+new_var_context (name, flags)
+ char *name;
+ int flags;
+{
+ VAR_CONTEXT *vc;
+
+ vc = (VAR_CONTEXT *)xmalloc (sizeof (VAR_CONTEXT));
+ vc->name = name ? savestring (name) : (char *)NULL;
+ vc->scope = variable_context;
+ vc->flags = flags;
+
+ vc->up = vc->down = (VAR_CONTEXT *)NULL;
+ vc->table = (HASH_TABLE *)NULL;
+
+ return vc;
+}
+
+/* Free a variable context and its data, including the hash table. Dispose
+ all of the variables. */
+void
+dispose_var_context (vc)
+ VAR_CONTEXT *vc;
+{
+ FREE (vc->name);
+
+ if (vc->table)
+ {
+ delete_all_variables (vc->table);
+ hash_dispose (vc->table);
+ }
+
+ free (vc);
+}
+
+/* Set VAR's scope level to the current variable context. */
+static int
+set_context (var)
+ SHELL_VAR *var;
+{
+ return (var->context = variable_context);
+}
+
+/* Make a new variable context with NAME and FLAGS and a HASH_TABLE of
+ temporary variables, and push it onto shell_variables. This is
+ for shell functions. */
+VAR_CONTEXT *
+push_var_context (name, flags, tempvars)
+ char *name;
+ int flags;
+ HASH_TABLE *tempvars;
+{
+ VAR_CONTEXT *vc;
+
+ vc = new_var_context (name, flags);
+ vc->table = tempvars;
+ if (tempvars)
+ {
+ /* Have to do this because the temp environment was created before
+ variable_context was incremented. */
+ flatten (tempvars, set_context, (VARLIST *)NULL, 0);
+ vc->flags |= VC_HASTMPVAR;
+ }
+ vc->down = shell_variables;
+ shell_variables->up = vc;
+
+ return (shell_variables = vc);
+}
+
+static void
+push_func_var (data)
+ PTR_T data;
+{
+ SHELL_VAR *var, *v;
+
+ var = (SHELL_VAR *)data;
+
+ if (tempvar_p (var) && (posixly_correct || (var->attributes & att_propagate)))
+ {
+ /* Make sure we have a hash table to store the variable in while it is
+ being propagated down to the global variables table. Create one if
+ we have to */
+ if ((vc_isfuncenv (shell_variables) || vc_istempenv (shell_variables)) && shell_variables->table == 0)
+ shell_variables->table = hash_create (0);
+ /* XXX - should we set v->context here? */
+ v = bind_variable_internal (var->name, value_cell (var), shell_variables->table, 0, 0);
+ if (shell_variables == global_variables)
+ var->attributes &= ~(att_tempvar|att_propagate);
+ else
+ shell_variables->flags |= VC_HASTMPVAR;
+ v->attributes |= var->attributes;
+ }
+ else
+ stupidly_hack_special_variables (var->name); /* XXX */
+
+ dispose_variable (var);
+}
+
+/* Pop the top context off of VCXT and dispose of it, returning the rest of
+ the stack. */
+void
+pop_var_context ()
+{
+ VAR_CONTEXT *ret, *vcxt;
+
+ vcxt = shell_variables;
+ if (vc_isfuncenv (vcxt) == 0)
+ {
+ internal_error (_("pop_var_context: head of shell_variables not a function context"));
+ return;
+ }
+
+ if (ret = vcxt->down)
+ {
+ ret->up = (VAR_CONTEXT *)NULL;
+ shell_variables = ret;
+ if (vcxt->table)
+ hash_flush (vcxt->table, push_func_var);
+ dispose_var_context (vcxt);
+ }
+ else
+ internal_error (_("pop_var_context: no global_variables context"));
+}
+
+/* Delete the HASH_TABLEs for all variable contexts beginning at VCXT, and
+ all of the VAR_CONTEXTs except GLOBAL_VARIABLES. */
+void
+delete_all_contexts (vcxt)
+ VAR_CONTEXT *vcxt;
+{
+ VAR_CONTEXT *v, *t;
+
+ for (v = vcxt; v != global_variables; v = t)
+ {
+ t = v->down;
+ dispose_var_context (v);
+ }
+
+ delete_all_variables (global_variables->table);
+ shell_variables = global_variables;
+}
+
+/* **************************************************************** */
+/* */
+/* Pushing and Popping temporary variable scopes */
+/* */
+/* **************************************************************** */
+
+VAR_CONTEXT *
+push_scope (flags, tmpvars)
+ int flags;
+ HASH_TABLE *tmpvars;
+{
+ return (push_var_context ((char *)NULL, flags, tmpvars));
+}
+
+static void
+push_exported_var (data)
+ PTR_T data;
+{
+ SHELL_VAR *var, *v;
+
+ var = (SHELL_VAR *)data;
+
+ /* If a temp var had its export attribute set, or it's marked to be
+ propagated, bind it in the previous scope before disposing it. */
+ /* XXX - This isn't exactly right, because all tempenv variables have the
+ export attribute set. */
+#if 0
+ if (exported_p (var) || (var->attributes & att_propagate))
+#else
+ if (tempvar_p (var) && exported_p (var) && (var->attributes & att_propagate))
+#endif
+ {
+ var->attributes &= ~att_tempvar; /* XXX */
+ v = bind_variable_internal (var->name, value_cell (var), shell_variables->table, 0, 0);
+ if (shell_variables == global_variables)
+ var->attributes &= ~att_propagate;
+ v->attributes |= var->attributes;
+ }
+ else
+ stupidly_hack_special_variables (var->name); /* XXX */
+
+ dispose_variable (var);
+}
+
+void
+pop_scope (is_special)
+ int is_special;
+{
+ VAR_CONTEXT *vcxt, *ret;
+
+ vcxt = shell_variables;
+ if (vc_istempscope (vcxt) == 0)
+ {
+ internal_error (_("pop_scope: head of shell_variables not a temporary environment scope"));
+ return;
+ }
+
+ ret = vcxt->down;
+ if (ret)
+ ret->up = (VAR_CONTEXT *)NULL;
+
+ shell_variables = ret;
+
+ /* Now we can take care of merging variables in VCXT into set of scopes
+ whose head is RET (shell_variables). */
+ FREE (vcxt->name);
+ if (vcxt->table)
+ {
+ if (is_special)
+ hash_flush (vcxt->table, push_func_var);
+ else
+ hash_flush (vcxt->table, push_exported_var);
+ hash_dispose (vcxt->table);
+ }
+ free (vcxt);
+
+ sv_ifs ("IFS"); /* XXX here for now */
+}
+
+/* **************************************************************** */
+/* */
+/* Pushing and Popping function contexts */
+/* */
+/* **************************************************************** */
+
+static WORD_LIST **dollar_arg_stack = (WORD_LIST **)NULL;
+static int dollar_arg_stack_slots;
+static int dollar_arg_stack_index;
+
+/* XXX - we might want to consider pushing and popping the `getopts' state
+ when we modify the positional parameters. */
+void
+push_context (name, is_subshell, tempvars)
+ char *name; /* function name */
+ int is_subshell;
+ HASH_TABLE *tempvars;
+{
+ if (is_subshell == 0)
+ push_dollar_vars ();
+ variable_context++;
+ push_var_context (name, VC_FUNCENV, tempvars);
+}
+
+/* Only called when subshell == 0, so we don't need to check, and can
+ unconditionally pop the dollar vars off the stack. */
+void
+pop_context ()
+{
+ pop_dollar_vars ();
+ variable_context--;
+ pop_var_context ();
+
+ sv_ifs ("IFS"); /* XXX here for now */
+}
+
+/* Save the existing positional parameters on a stack. */
+void
+push_dollar_vars ()
+{
+ if (dollar_arg_stack_index + 2 > dollar_arg_stack_slots)
+ {
+ dollar_arg_stack = (WORD_LIST **)
+ xrealloc (dollar_arg_stack, (dollar_arg_stack_slots += 10)
+ * sizeof (WORD_LIST *));
+ }
+ dollar_arg_stack[dollar_arg_stack_index++] = list_rest_of_args ();
+ dollar_arg_stack[dollar_arg_stack_index] = (WORD_LIST *)NULL;
+}
+
+/* Restore the positional parameters from our stack. */
+void
+pop_dollar_vars ()
+{
+ if (!dollar_arg_stack || dollar_arg_stack_index == 0)
+ return;
+
+ remember_args (dollar_arg_stack[--dollar_arg_stack_index], 1);
+ dispose_words (dollar_arg_stack[dollar_arg_stack_index]);
+ dollar_arg_stack[dollar_arg_stack_index] = (WORD_LIST *)NULL;
+ set_dollar_vars_unchanged ();
+}
+
+void
+dispose_saved_dollar_vars ()
+{
+ if (!dollar_arg_stack || dollar_arg_stack_index == 0)
+ return;
+
+ dispose_words (dollar_arg_stack[dollar_arg_stack_index]);
+ dollar_arg_stack[dollar_arg_stack_index] = (WORD_LIST *)NULL;
+}
+
+/* Manipulate the special BASH_ARGV and BASH_ARGC variables. */
+
+void
+push_args (list)
+ WORD_LIST *list;
+{
+#if defined (ARRAY_VARS) && defined (DEBUGGER)
+ SHELL_VAR *bash_argv_v, *bash_argc_v;
+ ARRAY *bash_argv_a, *bash_argc_a;
+ WORD_LIST *l;
+ arrayind_t i;
+ char *t;
+
+ GET_ARRAY_FROM_VAR ("BASH_ARGV", bash_argv_v, bash_argv_a);
+ GET_ARRAY_FROM_VAR ("BASH_ARGC", bash_argc_v, bash_argc_a);
+
+ for (l = list, i = 0; l; l = l->next, i++)
+ array_push (bash_argv_a, l->word->word);
+
+ t = itos (i);
+ array_push (bash_argc_a, t);
+ free (t);
+#endif /* ARRAY_VARS && DEBUGGER */
+}
+
+/* Remove arguments from BASH_ARGV array. Pop top element off BASH_ARGC
+ array and use that value as the count of elements to remove from
+ BASH_ARGV. */
+void
+pop_args ()
+{
+#if defined (ARRAY_VARS) && defined (DEBUGGER)
+ SHELL_VAR *bash_argv_v, *bash_argc_v;
+ ARRAY *bash_argv_a, *bash_argc_a;
+ ARRAY_ELEMENT *ce;
+ intmax_t i;
+
+ GET_ARRAY_FROM_VAR ("BASH_ARGV", bash_argv_v, bash_argv_a);
+ GET_ARRAY_FROM_VAR ("BASH_ARGC", bash_argc_v, bash_argc_a);
+
+ ce = array_shift (bash_argc_a, 1, 0);
+ if (ce == 0 || legal_number (element_value (ce), &i) == 0)
+ i = 0;
+
+ for ( ; i > 0; i--)
+ array_pop (bash_argv_a);
+ array_dispose_element (ce);
+#endif /* ARRAY_VARS && DEBUGGER */
+}
+
+/*************************************************
+ * *
+ * Functions to manage special variables *
+ * *
+ *************************************************/
+
+/* Extern declarations for variables this code has to manage. */
+extern int eof_encountered, eof_encountered_limit, ignoreeof;
+
+#if defined (READLINE)
+extern int hostname_list_initialized;
+#endif
+
+/* An alist of name.function for each special variable. Most of the
+ functions don't do much, and in fact, this would be faster with a
+ switch statement, but by the end of this file, I am sick of switch
+ statements. */
+
+#define SET_INT_VAR(name, intvar) intvar = find_variable (name) != 0
+
+/* This table will be sorted with qsort() the first time it's accessed. */
+struct name_and_function {
+ char *name;
+ sh_sv_func_t *function;
+};
+
+static struct name_and_function special_vars[] = {
+ { "BASH_COMPAT", sv_shcompat },
+ { "BASH_XTRACEFD", sv_xtracefd },
+
+#if defined (JOB_CONTROL)
+ { "CHILD_MAX", sv_childmax },
+#endif
+
+#if defined (READLINE)
+# if defined (STRICT_POSIX)
+ { "COLUMNS", sv_winsize },
+# endif
+ { "COMP_WORDBREAKS", sv_comp_wordbreaks },
+#endif
+
+ { "FUNCNEST", sv_funcnest },
+
+ { "GLOBIGNORE", sv_globignore },
+
+#if defined (HISTORY)
+ { "HISTCONTROL", sv_history_control },
+ { "HISTFILESIZE", sv_histsize },
+ { "HISTIGNORE", sv_histignore },
+ { "HISTSIZE", sv_histsize },
+ { "HISTTIMEFORMAT", sv_histtimefmt },
+#endif
+
+#if defined (__CYGWIN__)
+ { "HOME", sv_home },
+#endif
+
+#if defined (READLINE)
+ { "HOSTFILE", sv_hostfile },
+#endif
+
+ { "IFS", sv_ifs },
+ { "IGNOREEOF", sv_ignoreeof },
+
+ { "LANG", sv_locale },
+ { "LC_ALL", sv_locale },
+ { "LC_COLLATE", sv_locale },
+ { "LC_CTYPE", sv_locale },
+ { "LC_MESSAGES", sv_locale },
+ { "LC_NUMERIC", sv_locale },
+ { "LC_TIME", sv_locale },
+
+#if defined (READLINE) && defined (STRICT_POSIX)
+ { "LINES", sv_winsize },
+#endif
+
+ { "MAIL", sv_mail },
+ { "MAILCHECK", sv_mail },
+ { "MAILPATH", sv_mail },
+
+ { "OPTERR", sv_opterr },
+ { "OPTIND", sv_optind },
+
+ { "PATH", sv_path },
+ { "POSIXLY_CORRECT", sv_strict_posix },
+
+#if defined (READLINE)
+ { "TERM", sv_terminal },
+ { "TERMCAP", sv_terminal },
+ { "TERMINFO", sv_terminal },
+#endif /* READLINE */
+
+ { "TEXTDOMAIN", sv_locale },
+ { "TEXTDOMAINDIR", sv_locale },
+
+#if defined (HAVE_TZSET)
+ { "TZ", sv_tz },
+#endif
+
+#if defined (HISTORY) && defined (BANG_HISTORY)
+ { "histchars", sv_histchars },
+#endif /* HISTORY && BANG_HISTORY */
+
+ { "ignoreeof", sv_ignoreeof },
+
+ { (char *)0, (sh_sv_func_t *)0 }
+};
+
+#define N_SPECIAL_VARS (sizeof (special_vars) / sizeof (special_vars[0]) - 1)
+
+static int
+sv_compare (sv1, sv2)
+ struct name_and_function *sv1, *sv2;
+{
+ int r;
+
+ if ((r = sv1->name[0] - sv2->name[0]) == 0)
+ r = strcmp (sv1->name, sv2->name);
+ return r;
+}
+
+static inline int
+find_special_var (name)
+ const char *name;
+{
+ register int i, r;
+
+ for (i = 0; special_vars[i].name; i++)
+ {
+ r = special_vars[i].name[0] - name[0];
+ if (r == 0)
+ r = strcmp (special_vars[i].name, name);
+ if (r == 0)
+ return i;
+ else if (r > 0)
+ /* Can't match any of rest of elements in sorted list. Take this out
+ if it causes problems in certain environments. */
+ break;
+ }
+ return -1;
+}
+
+/* The variable in NAME has just had its state changed. Check to see if it
+ is one of the special ones where something special happens. */
+void
+stupidly_hack_special_variables (name)
+ char *name;
+{
+ static int sv_sorted = 0;
+ int i;
+
+ if (sv_sorted == 0) /* shouldn't need, but it's fairly cheap. */
+ {
+ qsort (special_vars, N_SPECIAL_VARS, sizeof (special_vars[0]),
+ (QSFUNC *)sv_compare);
+ sv_sorted = 1;
+ }
+
+ i = find_special_var (name);
+ if (i != -1)
+ (*(special_vars[i].function)) (name);
+}
+
+/* Special variables that need hooks to be run when they are unset as part
+ of shell reinitialization should have their sv_ functions run here. */
+void
+reinit_special_variables ()
+{
+#if defined (READLINE)
+ sv_comp_wordbreaks ("COMP_WORDBREAKS");
+#endif
+ sv_globignore ("GLOBIGNORE");
+ sv_opterr ("OPTERR");
+}
+
+void
+sv_ifs (name)
+ char *name;
+{
+ SHELL_VAR *v;
+
+ v = find_variable ("IFS");
+ setifs (v);
+}
+
+/* What to do just after the PATH variable has changed. */
+void
+sv_path (name)
+ char *name;
+{
+ /* hash -r */
+ phash_flush ();
+}
+
+/* What to do just after one of the MAILxxxx variables has changed. NAME
+ is the name of the variable. This is called with NAME set to one of
+ MAIL, MAILCHECK, or MAILPATH. */
+void
+sv_mail (name)
+ char *name;
+{
+ /* If the time interval for checking the files has changed, then
+ reset the mail timer. Otherwise, one of the pathname vars
+ to the users mailbox has changed, so rebuild the array of
+ filenames. */
+ if (name[4] == 'C') /* if (strcmp (name, "MAILCHECK") == 0) */
+ reset_mail_timer ();
+ else
+ {
+ free_mail_files ();
+ remember_mail_dates ();
+ }
+}
+
+void
+sv_funcnest (name)
+ char *name;
+{
+ SHELL_VAR *v;
+ intmax_t num;
+
+ v = find_variable (name);
+ if (v == 0)
+ funcnest_max = 0;
+ else if (legal_number (value_cell (v), &num) == 0)
+ funcnest_max = 0;
+ else
+ funcnest_max = num;
+}
+
+/* What to do when GLOBIGNORE changes. */
+void
+sv_globignore (name)
+ char *name;
+{
+ if (privileged_mode == 0)
+ setup_glob_ignore (name);
+}
+
+#if defined (READLINE)
+void
+sv_comp_wordbreaks (name)
+ char *name;
+{
+ SHELL_VAR *sv;
+
+ sv = find_variable (name);
+ if (sv == 0)
+ reset_completer_word_break_chars ();
+}
+
+/* What to do just after one of the TERMxxx variables has changed.
+ If we are an interactive shell, then try to reset the terminal
+ information in readline. */
+void
+sv_terminal (name)
+ char *name;
+{
+ if (interactive_shell && no_line_editing == 0)
+ rl_reset_terminal (get_string_value ("TERM"));
+}
+
+void
+sv_hostfile (name)
+ char *name;
+{
+ SHELL_VAR *v;
+
+ v = find_variable (name);
+ if (v == 0)
+ clear_hostname_list ();
+ else
+ hostname_list_initialized = 0;
+}
+
+#if defined (STRICT_POSIX)
+/* In strict posix mode, we allow assignments to LINES and COLUMNS (and values
+ found in the initial environment) to override the terminal size reported by
+ the kernel. */
+void
+sv_winsize (name)
+ char *name;
+{
+ SHELL_VAR *v;
+ intmax_t xd;
+ int d;
+
+ if (posixly_correct == 0 || interactive_shell == 0 || no_line_editing)
+ return;
+
+ v = find_variable (name);
+ if (v == 0 || var_isnull (v))
+ rl_reset_screen_size ();
+ else
+ {
+ if (legal_number (value_cell (v), &xd) == 0)
+ return;
+ winsize_assignment = 1;
+ d = xd; /* truncate */
+ if (name[0] == 'L') /* LINES */
+ rl_set_screen_size (d, -1);
+ else /* COLUMNS */
+ rl_set_screen_size (-1, d);
+ winsize_assignment = 0;
+ }
+}
+#endif /* STRICT_POSIX */
+#endif /* READLINE */
+
+/* Update the value of HOME in the export environment so tilde expansion will
+ work on cygwin. */
+#if defined (__CYGWIN__)
+sv_home (name)
+ char *name;
+{
+ array_needs_making = 1;
+ maybe_make_export_env ();
+}
+#endif
+
+#if defined (HISTORY)
+/* What to do after the HISTSIZE or HISTFILESIZE variables change.
+ If there is a value for this HISTSIZE (and it is numeric), then stifle
+ the history. Otherwise, if there is NO value for this variable,
+ unstifle the history. If name is HISTFILESIZE, and its value is
+ numeric, truncate the history file to hold no more than that many
+ lines. */
+void
+sv_histsize (name)
+ char *name;
+{
+ char *temp;
+ intmax_t num;
+ int hmax;
+
+ temp = get_string_value (name);
+
+ if (temp && *temp)
+ {
+ if (legal_number (temp, &num))
+ {
+ hmax = num;
+ if (hmax < 0 && name[4] == 'S')
+ unstifle_history (); /* unstifle history if HISTSIZE < 0 */
+ else if (name[4] == 'S')
+ {
+ stifle_history (hmax);
+ hmax = where_history ();
+ if (history_lines_this_session > hmax)
+ history_lines_this_session = hmax;
+ }
+ else if (hmax >= 0) /* truncate HISTFILE if HISTFILESIZE >= 0 */
+ {
+ history_truncate_file (get_string_value ("HISTFILE"), hmax);
+ if (hmax <= history_lines_in_file)
+ history_lines_in_file = hmax;
+ }
+ }
+ }
+ else if (name[4] == 'S')
+ unstifle_history ();
+}
+
+/* What to do after the HISTIGNORE variable changes. */
+void
+sv_histignore (name)
+ char *name;
+{
+ setup_history_ignore (name);
+}
+
+/* What to do after the HISTCONTROL variable changes. */
+void
+sv_history_control (name)
+ char *name;
+{
+ char *temp;
+ char *val;
+ int tptr;
+
+ history_control = 0;
+ temp = get_string_value (name);
+
+ if (temp == 0 || *temp == 0)
+ return;
+
+ tptr = 0;
+ while (val = extract_colon_unit (temp, &tptr))
+ {
+ if (STREQ (val, "ignorespace"))
+ history_control |= HC_IGNSPACE;
+ else if (STREQ (val, "ignoredups"))
+ history_control |= HC_IGNDUPS;
+ else if (STREQ (val, "ignoreboth"))
+ history_control |= HC_IGNBOTH;
+ else if (STREQ (val, "erasedups"))
+ history_control |= HC_ERASEDUPS;
+
+ free (val);
+ }
+}
+
+#if defined (BANG_HISTORY)
+/* Setting/unsetting of the history expansion character. */
+void
+sv_histchars (name)
+ char *name;
+{
+ char *temp;
+
+ temp = get_string_value (name);
+ if (temp)
+ {
+ history_expansion_char = *temp;
+ if (temp[0] && temp[1])
+ {
+ history_subst_char = temp[1];
+ if (temp[2])
+ history_comment_char = temp[2];
+ }
+ }
+ else
+ {
+ history_expansion_char = '!';
+ history_subst_char = '^';
+ history_comment_char = '#';
+ }
+}
+#endif /* BANG_HISTORY */
+
+void
+sv_histtimefmt (name)
+ char *name;
+{
+ SHELL_VAR *v;
+
+ if (v = find_variable (name))
+ {
+ if (history_comment_char == 0)
+ history_comment_char = '#';
+ }
+ history_write_timestamps = (v != 0);
+}
+#endif /* HISTORY */
+
+#if defined (HAVE_TZSET)
+void
+sv_tz (name)
+ char *name;
+{
+ if (chkexport (name))
+ tzset ();
+}
+#endif
+
+/* If the variable exists, then the value of it can be the number
+ of times we actually ignore the EOF. The default is small,
+ (smaller than csh, anyway). */
+void
+sv_ignoreeof (name)
+ char *name;
+{
+ SHELL_VAR *tmp_var;
+ char *temp;
+
+ eof_encountered = 0;
+
+ tmp_var = find_variable (name);
+ ignoreeof = tmp_var != 0;
+ temp = tmp_var ? value_cell (tmp_var) : (char *)NULL;
+ if (temp)
+ eof_encountered_limit = (*temp && all_digits (temp)) ? atoi (temp) : 10;
+ set_shellopts (); /* make sure `ignoreeof' is/is not in $SHELLOPTS */
+}
+
+void
+sv_optind (name)
+ char *name;
+{
+ char *tt;
+ int s;
+
+ tt = get_string_value ("OPTIND");
+ if (tt && *tt)
+ {
+ s = atoi (tt);
+
+ /* According to POSIX, setting OPTIND=1 resets the internal state
+ of getopt (). */
+ if (s < 0 || s == 1)
+ s = 0;
+ }
+ else
+ s = 0;
+ getopts_reset (s);
+}
+
+void
+sv_opterr (name)
+ char *name;
+{
+ char *tt;
+
+ tt = get_string_value ("OPTERR");
+ sh_opterr = (tt && *tt) ? atoi (tt) : 1;
+}
+
+void
+sv_strict_posix (name)
+ char *name;
+{
+ SET_INT_VAR (name, posixly_correct);
+ posix_initialize (posixly_correct);
+#if defined (READLINE)
+ if (interactive_shell)
+ posix_readline_initialize (posixly_correct);
+#endif /* READLINE */
+ set_shellopts (); /* make sure `posix' is/is not in $SHELLOPTS */
+}
+
+void
+sv_locale (name)
+ char *name;
+{
+ char *v;
+ int r;
+
+ v = get_string_value (name);
+ if (name[0] == 'L' && name[1] == 'A') /* LANG */
+ r = set_lang (name, v);
+ else
+ r = set_locale_var (name, v); /* LC_*, TEXTDOMAIN* */
+
+#if 1
+ if (r == 0 && posixly_correct)
+ last_command_exit_value = 1;
+#endif
+}
+
+#if defined (ARRAY_VARS)
+void
+set_pipestatus_array (ps, nproc)
+ int *ps;
+ int nproc;
+{
+ SHELL_VAR *v;
+ ARRAY *a;
+ ARRAY_ELEMENT *ae;
+ register int i;
+ char *t, tbuf[INT_STRLEN_BOUND(int) + 1];
+
+ v = find_variable ("PIPESTATUS");
+ if (v == 0)
+ v = make_new_array_variable ("PIPESTATUS");
+ if (array_p (v) == 0)
+ return; /* Do nothing if not an array variable. */
+ a = array_cell (v);
+
+ if (a == 0 || array_num_elements (a) == 0)
+ {
+ for (i = 0; i < nproc; i++) /* was ps[i] != -1, not i < nproc */
+ {
+ t = inttostr (ps[i], tbuf, sizeof (tbuf));
+ array_insert (a, i, t);
+ }
+ return;
+ }
+
+ /* Fast case */
+ if (array_num_elements (a) == nproc && nproc == 1)
+ {
+ ae = element_forw (a->head);
+ free (element_value (ae));
+ ae->value = itos (ps[0]);
+ }
+ else if (array_num_elements (a) <= nproc)
+ {
+ /* modify in array_num_elements members in place, then add */
+ ae = a->head;
+ for (i = 0; i < array_num_elements (a); i++)
+ {
+ ae = element_forw (ae);
+ free (element_value (ae));
+ ae->value = itos (ps[i]);
+ }
+ /* add any more */
+ for ( ; i < nproc; i++)
+ {
+ t = inttostr (ps[i], tbuf, sizeof (tbuf));
+ array_insert (a, i, t);
+ }
+ }
+ else
+ {
+ /* deleting elements. it's faster to rebuild the array. */
+ array_flush (a);
+ for (i = 0; ps[i] != -1; i++)
+ {
+ t = inttostr (ps[i], tbuf, sizeof (tbuf));
+ array_insert (a, i, t);
+ }
+ }
+}
+
+ARRAY *
+save_pipestatus_array ()
+{
+ SHELL_VAR *v;
+ ARRAY *a, *a2;
+
+ v = find_variable ("PIPESTATUS");
+ if (v == 0 || array_p (v) == 0 || array_cell (v) == 0)
+ return ((ARRAY *)NULL);
+
+ a = array_cell (v);
+ a2 = array_copy (array_cell (v));
+
+ return a2;
+}
+
+void
+restore_pipestatus_array (a)
+ ARRAY *a;
+{
+ SHELL_VAR *v;
+ ARRAY *a2;
+
+ v = find_variable ("PIPESTATUS");
+ /* XXX - should we still assign even if existing value is NULL? */
+ if (v == 0 || array_p (v) == 0 || array_cell (v) == 0)
+ return;
+
+ a2 = array_cell (v);
+ var_setarray (v, a);
+
+ array_dispose (a2);
+}
+#endif
+
+void
+set_pipestatus_from_exit (s)
+ int s;
+{
+#if defined (ARRAY_VARS)
+ static int v[2] = { 0, -1 };
+
+ v[0] = s;
+ set_pipestatus_array (v, 1);
+#endif
+}
+
+void
+sv_xtracefd (name)
+ char *name;
+{
+ SHELL_VAR *v;
+ char *t, *e;
+ int fd;
+ FILE *fp;
+
+ v = find_variable (name);
+ if (v == 0)
+ {
+ xtrace_reset ();
+ return;
+ }
+
+ t = value_cell (v);
+ if (t == 0 || *t == 0)
+ xtrace_reset ();
+ else
+ {
+ fd = (int)strtol (t, &e, 10);
+ if (e != t && *e == '\0' && sh_validfd (fd))
+ {
+ fp = fdopen (fd, "w");
+ if (fp == 0)
+ internal_error (_("%s: %s: cannot open as FILE"), name, value_cell (v));
+ else
+ xtrace_set (fd, fp);
+ }
+ else
+ internal_error (_("%s: %s: invalid value for trace file descriptor"), name, value_cell (v));
+ }
+}
+
+#define MIN_COMPAT_LEVEL 31
+
+void
+sv_shcompat (name)
+ char *name;
+{
+ SHELL_VAR *v;
+ char *val;
+ int tens, ones, compatval;
+
+ v = find_variable (name);
+ if (v == 0)
+ {
+ shell_compatibility_level = DEFAULT_COMPAT_LEVEL;
+ set_compatibility_opts ();
+ return;
+ }
+ val = value_cell (v);
+ if (val == 0 || *val == '\0')
+ {
+ shell_compatibility_level = DEFAULT_COMPAT_LEVEL;
+ set_compatibility_opts ();
+ return;
+ }
+ /* Handle decimal-like compatibility version specifications: 4.2 */
+ if (isdigit (val[0]) && val[1] == '.' && isdigit (val[2]) && val[3] == 0)
+ {
+ tens = val[0] - '0';
+ ones = val[2] - '0';
+ compatval = tens*10 + ones;
+ }
+ /* Handle integer-like compatibility version specifications: 42 */
+ else if (isdigit (val[0]) && isdigit (val[1]) && val[2] == 0)
+ {
+ tens = val[0] - '0';
+ ones = val[1] - '0';
+ compatval = tens*10 + ones;
+ }
+ else
+ {
+compat_error:
+ internal_error (_("%s: %s: compatibility value out of range"), name, val);
+ shell_compatibility_level = DEFAULT_COMPAT_LEVEL;
+ set_compatibility_opts ();
+ return;
+ }
+
+ if (compatval < MIN_COMPAT_LEVEL || compatval > DEFAULT_COMPAT_LEVEL)
+ goto compat_error;
+
+ shell_compatibility_level = compatval;
+ set_compatibility_opts ();
+}
+
+#if defined (JOB_CONTROL)
+void
+sv_childmax (name)
+ char *name;
+{
+ char *tt;
+ int s;
+
+ tt = get_string_value (name);
+ s = (tt && *tt) ? atoi (tt) : 0;
+ set_maxchild (s);
+}
+#endif
projects / thirdparty / bash.git / commitdiff
