only viable way to distribute automatic build rules for software, but
one quickly runs into @command{make}'s numerous limitations. Its lack of
support for automatic dependency tracking, recursive builds in
-subdirectories, reliable timestamps (e.g. for network filesystems), and
+subdirectories, reliable timestamps (e.g., for network filesystems), and
so on, mean that developers must painfully (and often incorrectly)
reinvent the wheel for each project. Portability is non-trivial, thanks
to the quirks of @command{make} on many systems. On top of all this is the
Automake may require that additional tools be present on the
@emph{developer's} machine. For example, the @code{Makefile.in} that
-the developer works with may not be portable (e.g. it might use special
+the developer works with may not be portable (e.g., it might use special
features of your compiler to automatically generate dependency
information). Running @code{make dist}, however, produces a
@file{hello-1.0.tar.gz} package (or whatever the program/version is)
extending an existing one. The former option is very attractive: all
sorts of optimizations could easily be implemented in the compiler and
many rigorous checks could be performed on the Autoconf program
-(e.g. rejecting any non-portable construct). Alternatively, you can
+(e.g., rejecting any non-portable construct). Alternatively, you can
extend an existing language, such as the @code{sh} (Bourne shell)
language.
Warnings about @samp{syntax} are enabled by default, and the environment
variable @code{WARNINGS}, a comma separated list of categories, is
-honored. @samp{autoconf -W @var{category}} will actually
+honored. @samp{autoconf -W @var{category}} will actually
behave as if you had run:
@example
@itemx $@{@var{separator}@}@@
All the arguments passed to @var{macro}, separated by the character
@var{sep} or the string @var{separator} (@samp{,} by default). Each
-argument is quoted, i.e. enclosed in a pair of square brackets.
+argument is quoted, i.e., enclosed in a pair of square brackets.
@item $*
@itemx $@var{sep}*
Installing the various components of the @sc{gnu} Build System can be
tedious: running @command{autopoint} for Gettext, @command{automake} for
-@file{Makefile.in} etc. in each directory. It may be needed either
+@file{Makefile.in} etc.@: in each directory. It may be needed either
because some tools such as @command{automake} have been updated on your
system, or because some of the sources such as @file{configure.ac} have
been updated, or finally, simply in order to install the @sc{gnu} Build
The macros @code{AC_CONFIG_FILES} and @code{AC_CONFIG_HEADERS} use
special @var{tag}s: they may have the form @samp{@var{output}} or
-@samp{@var{output}:@var{inputs}}. The file @var{output} is instantiated
+@samp{@var{output}:@var{inputs}}. The file @var{output} is instantiated
from its templates, @var{inputs} (defaulting to @samp{@var{output}.in}).
For instance
@defvar prefix
@ovindex prefix
-The common installation prefix for all files. If @var{exec_prefix}
+The common installation prefix for all files. If @var{exec_prefix}
is defined to a different value, @var{prefix} is used only for
architecture-independent files.
@end defvar
A corollary is that you should not use these variables except in
Makefiles. For instance, instead of trying to evaluate @code{datadir}
-in @file{configure} and hardcoding it in Makefiles using
-e.g. @samp{AC_DEFINE_UNQUOTED(DATADIR, "$datadir")}, you should add
+in @file{configure} and hard-coding it in Makefiles using
+e.g., @samp{AC_DEFINE_UNQUOTED(DATADIR, "$datadir")}, you should add
@samp{-DDATADIR="$(datadir)"} to your @code{CPPFLAGS}.
Similarly you should not rely on @code{AC_OUTPUT_FILES} to replace
@example
@group
edit = sed \
- -e 's,@@datadir\@@,$(pkgdatadir),g' \
- -e 's,@@prefix\@@,$(prefix),g'
+ -e 's,@@datadir\@@,$(pkgdatadir),g' \
+ -e 's,@@prefix\@@,$(prefix),g'
@end group
autoconf autoheader: Makefile
#if HAVE_UNISTD_H
# include <unistd.h>
#else
-/* We are in trouble. */
+/* We are in trouble. */
#endif
@end group
@end example
@itemx -W @var{category}
@evindex WARNINGS
Report the warnings related to @var{category} (which can actually be a
-comma separated list). Current categories include:
+comma separated list). Current categories include:
@table @samp
@item obsolete
@end example
If a given @var{dir} contains @command{configure.gnu}, it is run instead
-of @command{configure}. This is for packages that might use a
+of @command{configure}. This is for packages that might use a
non-Autoconf script @command{Configure}, which can't be called through a
wrapper @command{configure} since it would be the same file on
-case-insensitive filesystems. Likewise, if a @var{dir} contains
+case-insensitive filesystems. Likewise, if a @var{dir} contains
@file{configure.ac} but no @command{configure}, the Cygnus
@command{configure} script found by @code{AC_CONFIG_AUX_DIR} is used.
@end example
You are strongly encouraged to declare the @var{variable} passed to
-@code{AC_CHECK_PROG} etc. as precious, @xref{Setting Output Variables},
+@code{AC_CHECK_PROG} etc.@: as precious, @xref{Setting Output Variables},
@code{AC_ARG_VAR}, for more details.
@defmac AC_CHECK_PROG (@var{variable}, @var{prog-to-check-for}, @var{value-if-found}, @ovar{value-if-not-found}, @ovar{path}, @ovar{reject})
Like @code{AC_CHECK_TOOL}, each of the tools in the list
@var{progs-to-check-for} are checked with a prefix of the host type as
determined by @code{AC_CANONICAL_HOST}, followed by a dash
-(@pxref{Canonicalizing}). If none of the tools can be found with a
-prefix, then the first one without a prefix is used. If a tool is found,
-set @var{variable} to the name of that program. If none of the tools in
+(@pxref{Canonicalizing}). If none of the tools can be found with a
+prefix, then the first one without a prefix is used. If a tool is found,
+set @var{variable} to the name of that program. If none of the tools in
the list are found, set @var{variable} to @var{value-if-not-found}; if
@var{value-if-not-found} is not specified, the value of @var{variable}
is not changed. Calls @code{AC_SUBST} for @var{variable}.
commands to run if the link fails. If @var{action-if-found} is not
specified, the default action will prepend @option{-l@var{library}} to
@code{LIBS} and define @samp{HAVE_LIB@var{library}} (in all
-capitals). This macro is intended to support building of @code{LIBS} in
+capitals). This macro is intended to support building of @code{LIBS} in
a right-to-left (least-dependent to most-dependent) fashion such that
library dependencies are satisfied as a natural side-effect of
-consecutive tests. Some linkers are very sensitive to library ordering
+consecutive tests. Some linkers are very sensitive to library ordering
so the order in which @code{LIBS} is generated is important to reliable
detection of libraries.
If linking with @var{library} results in unresolved symbols that would
be resolved by linking with additional libraries, give those libraries
as the @var{other-libraries} argument, separated by spaces:
-e.g. @option{-lXt -lX11}. Otherwise, this macro will fail to detect
+e.g., @option{-lXt -lX11}. Otherwise, this macro will fail to detect
that @var{library} is present, because linking the test program will
-always fail with unresolved symbols. The @var{other-libraries} argument
+always fail with unresolved symbols. The @var{other-libraries} argument
should be limited to cases where it is desirable to test for one library
in the presence of another that is not already in @code{LIBS}.
@end defmac
If linking with @var{library} results in unresolved symbols that would
be resolved by linking with additional libraries, give those libraries
as the @var{other-libraries} argument, separated by spaces:
-e.g. @option{-lXt -lX11}. Otherwise, this macro will fail to detect
+e.g., @option{-lXt -lX11}. Otherwise, this macro will fail to detect
that @var{function} is present, because linking the test program will
always fail with unresolved symbols.
@end defmac
@item @code{sscanf}
@c @fuindex sscanf
@prindex @code{sscanf}
-On various old systems, e.g. HP-UX 9, @code{sscanf} requires that its
+On various old systems, e.g., HP-UX 9, @code{sscanf} requires that its
input string be writable (though it doesn't actually change it). This
can be a problem when using @command{gcc} since it normally puts
constant strings in read-only memory
@prindex @code{va_copy}
The ISO C99 standard provides @code{va_copy} for copying
@code{va_list} variables. It may be available in older environments
-too, though possibly as @code{__va_copy} (eg. @command{gcc} in strict
+too, though possibly as @code{__va_copy} (e.g., @command{gcc} in strict
C89 mode). These can be tested with @code{#ifdef}. A fallback to
@code{memcpy (&dst, &src, sizeof(va_list))} will give maximum
portability.
@c @fuindex va_list
@prindex @code{va_list}
@code{va_list} is not necessarily just a pointer. It can be a
-@code{struct} (eg. @command{gcc} on Alpha), which means @code{NULL} is
-not portable. Or it can be an array (eg. @command{gcc} in some
+@code{struct} (e.g., @command{gcc} on Alpha), which means @code{NULL} is
+not portable. Or it can be an array (e.g., @command{gcc} in some
PowerPC configurations), which means as a function parameter it can be
effectively call-by-reference and library routines might modify the
-value back in the caller (eg. @code{vsnprintf} in the GNU C Library
+value back in the caller (e.g., @code{vsnprintf} in the GNU C Library
2.1).
@item Signed @code{>>}
@prindex @code{fork}
@c @fuindex vfork
@prindex @code{vfork}
-This macro checks for the @code{fork} and @code{vfork} functions. If a
-working @code{fork} is found, define @code{HAVE_WORKING_FORK}. This macro
+This macro checks for the @code{fork} and @code{vfork} functions. If a
+working @code{fork} is found, define @code{HAVE_WORKING_FORK}. This macro
checks whether @code{fork} is just a stub by trying to run it.
-If @file{vfork.h} is found, define @code{HAVE_VFORK_H}. If a working
-@code{vfork} is found, define @code{HAVE_WORKING_VFORK}. Otherwise,
+If @file{vfork.h} is found, define @code{HAVE_VFORK_H}. If a working
+@code{vfork} is found, define @code{HAVE_WORKING_VFORK}. Otherwise,
define @code{vfork} to be @code{fork} for backward compatibility with
-previous versions of @command{autoconf}. This macro checks for several known
+previous versions of @command{autoconf}. This macro checks for several known
errors in implementations of @code{vfork} and considers the system to not
-have a working @code{vfork} if it detects any of them. It is not considered
+have a working @code{vfork} if it detects any of them. It is not considered
to be an implementation error if a child's invocation of @code{signal}
modifies the parent's signal handler, since child processes rarely change
their signal handlers.
Note that this macro replaces the obsolete @code{AC_LIBOBJ_DECL}, with
slightly different semantics: the old macro took the function name,
-e.g. @code{foo}, as its argument rather than the file name.
+e.g., @code{foo}, as its argument rather than the file name.
@end defmac
@defmac AC_LIBSOURCES (@var{files})
additions. Please help us keeping it as complete as possible.
@table @asis
-@item @file{inttypes.h} vs. @file{stdint.h}
+@item @file{inttypes.h} vs.@: @file{stdint.h}
Paul Eggert notes that: ISO C 1999 says that @file{inttypes.h} includes
@file{stdint.h}, so there's no need to include @file{stdint.h}
separately in a standard environment. Many implementations have
-@file{inttypes.h} but not @file{stdint.h} (e.g. Solaris 7), but I don't
+@file{inttypes.h} but not @file{stdint.h} (e.g., Solaris 7), but I don't
know of any implementation that has @file{stdint.h} but not
@file{inttypes.h}. Nor do I know of any free software that includes
@file{stdint.h}; @file{stdint.h} seems to be a creation of the committee.
@defmac AC_HEADER_STAT
@acindex HEADER_STAT
@acindex STAT_MACROS_BROKEN
-If the macros @code{S_ISDIR}, @code{S_ISREG} et al. defined in
+If the macros @code{S_ISDIR}, @code{S_ISREG}, etc.@: defined in
@file{sys/stat.h} do not work properly (returning false positives),
define @code{STAT_MACROS_BROKEN}. This is the case on Tektronix UTekV,
Amdahl UTS and Motorola System V/88.
@defmac AC_F77_LIBRARY_LDFLAGS
@acindex F77_LIBRARY_LDFLAGS
@ovindex FLIBS
-Determine the linker flags (e.g. @option{-L} and @option{-l}) for the
+Determine the linker flags (e.g., @option{-L} and @option{-l}) for the
@dfn{Fortran 77 intrinsic and run-time libraries} that are required to
successfully link a Fortran 77 program or shared library. The output
variable @code{FLIBS} is set to these flags.
This macro is intended to be used in those situations when it is
-necessary to mix, e.g. C++ and Fortran 77 source code into a single
+necessary to mix, e.g., C++ and Fortran 77 source code into a single
program or shared library (@pxref{Mixing Fortran 77 With C and C++,,,
automake, GNU Automake}).
With many compilers, the Fortran libraries detected by
@code{AC_F77_LIBRARY_LDFLAGS} provide their own @code{main} entry
function that initializes things like Fortran I/O, and which then calls
-a user-provided entry function named e.g. @code{MAIN__} to run the
+a user-provided entry function named (say) @code{MAIN__} to run the
user's program. The @code{AC_F77_DUMMY_MAIN} or @code{AC_F77_MAIN}
macro figures out how to deal with this interaction.
solution was found, and @code{none} when no such dummy main is needed.
By default, @var{action-if-found} defines @code{F77_DUMMY_MAIN} to the
-name of this routine (e.g. @code{MAIN__}) @emph{if} it is required.
+name of this routine (e.g., @code{MAIN__}) @emph{if} it is required.
@ovar{action-if-not-found} defaults to exiting with an error.
In order to link with Fortran routines, the user's C/C++ program should
@acindex F77_MAIN
@cvindex F77_MAIN
As discussed above for @code{AC_F77_DUMMY_MAIN}, many Fortran libraries
-allow you to provide an entry point called e.g. @code{MAIN__} instead of
+allow you to provide an entry point called (say) @code{MAIN__} instead of
the usual @code{main}, which is then called by a @code{main} function in
the Fortran libraries that initializes things like Fortran I/O. The
@code{AC_F77_MAIN} macro detects whether it is @emph{possible} to
name-mangling scheme of the Fortran 77 compiler, there may be Fortran 77
compilers that it doesn't support yet. In this case, the above code
will generate a compile-time error, but some other behavior
-(e.g. disabling Fortran-related features) can be induced by checking
+(e.g., disabling Fortran-related features) can be induced by checking
whether the @code{F77_FUNC} macro is defined.
Now, to call that routine from a C program, we would do something like:
@end example
If the Fortran 77 identifier contains an underscore
-(e.g. @code{foo_bar}), you should use @code{F77_FUNC_} instead of
+(e.g., @code{foo_bar}), you should use @code{F77_FUNC_} instead of
@code{F77_FUNC} (with the same arguments). This is because some Fortran
77 compilers mangle names differently if they contain an underscore.
@end defmac
@var{input}.
This macro uses @code{CPPFLAGS}, but not @code{CFLAGS}, because
-@option{-g}, @option{-O}, etc. are not valid options to many C
+@option{-g}, @option{-O}, etc.@: are not valid options to many C
preprocessors.
@end defmac
sensitive) or HFS+ (case preserving). By default Apple wants you to
install the OS on HFS+. Unfortunately, there are some pieces of
software which really need to be built on UFS. We may want to rebuild
-darwin to have both UFS and HFS+ available (and put the /local/build
+Darwin to have both UFS and HFS+ available (and put the /local/build
tree on the UFS).
@item @sc{qnx 4.25}
@c QNX Neutrino.
@sc{qnx} is a realtime operating system running on Intel architecture
meant to be scalable from the small embedded systems to hundred
-processor super-computer. It claims to be @sc{posix} certified. More
+processor super-computer. It claims to be @sc{posix} certified. More
information is available on the @href{www.qnx.com, @sc{qnx} home page},
including the @href{http://support.qnx.com/support/docs/qnx4/, @sc{qnx}
man pages}.
Autoconf-generated @command{configure} scripts check for the C compiler and
its features by default. Packages that use other programming languages
-(maybe more than one, e.g. C and C++) need to test features of the
+(maybe more than one, e.g., C and C++) need to test features of the
compilers for the respective languages. The following macros determine
which programming language is used in the subsequent tests in
@file{configure.ac}.
If neither @var{value} nor @var{description} are given, then
@var{value} defaults to 1 instead of to the empty string. This is for
-backwards compatiblity with older versions of Autoconf, but this usage
+backwards compatibility with older versions of Autoconf, but this usage
is obsolescent and may be withdrawn in future versions of Autoconf.
@end defmac
It is very common to find buggy macros using @code{AC_CACHE_VAL} or
@code{AC_CACHE_CHECK}, because people are tempted to call
-@code{AC_DEFINE} in the @var{commands-to-set-it}. Instead, the code that
+@code{AC_DEFINE} in the @var{commands-to-set-it}. Instead, the code that
@emph{follows} the call to @code{AC_CACHE_VAL} should call
@code{AC_DEFINE}, by examining the value of the cache variable. For
instance, the following macro is broken:
@samp{ac}.
@item @code{_cv_}
-Indicates that this shell variable is a cache value. This string
+Indicates that this shell variable is a cache value. This string
@emph{must} be present in the variable name, including the leading
underscore.
file will gradually accumulate information whenever someone runs a new
@command{configure} script. (Running @command{configure} merges the new cache
results with the existing cache file.) This may cause problems,
-however, if the system configuration (e.g. the installed libraries or
+however, if the system configuration (e.g., the installed libraries or
compilers) changes and the stale cache file is not deleted.
@node Cache Checkpointing
@defmac AC_MSG_NOTICE (@var{message})
@acindex MSG_NOTICE
-Deliver the @var{message} to the user. It is useful mainly to print a
+Deliver the @var{message} to the user. It is useful mainly to print a
general description of the overall purpose of a group of feature checks,
e.g.,
Warnings about @samp{syntax} are enabled by default, and the environment
variable @code{WARNINGS}, a comma separated list of categories, is
-honored. @command{autom4te -W @var{category}} will actually
+honored. @command{autom4te -W @var{category}} will actually
behave as if you had run:
@example
needed.
The @var{format} is a regular string, with newlines if desired, and
-several special escape codes. It defaults to @samp{$f:$l:$n:$%}. It can
+several special escape codes. It defaults to @samp{$f:$l:$n:$%}. It can
use the following special escapes:
@table @samp
@itemx $@{@var{separator}@}@@
All the arguments passed to @var{macro}, separated by the character
@var{sep} or the string @var{separator} (@samp{,} by default). Each
-argument is quoted, i.e. enclosed in a pair of square brackets.
+argument is quoted, i.e., enclosed in a pair of square brackets.
@item $*
@itemx $@var{sep}*
Cache the traces of @var{macro}, but do not enable traces. This is
especially important to save cpu cycles in the future. For instance,
when invoked, @command{autoconf} preselects all the macros that
-@command{autoheader}, @command{automake}, @command{autoreconf} etc. will
+@command{autoheader}, @command{automake}, @command{autoreconf} etc.@: will
trace, so that running @command{m4} is not needed to trace them: the
cache suffices. This results in a huge speed-up.
@end table
according to the Webster's Revised Unabridged Dictionary (1913):
@quotation
-Mash \Mash\, n. [Akin to G. meisch, maisch, meische, maische, mash,
-wash, and prob. to AS. miscian to mix. See ``Mix''.]
+Mash \Mash\, n. [Akin to G. meisch, maisch, meische, maische, mash,
+wash, and prob. to AS.@: miscian to mix. See ``Mix''.]
@enumerate 1
@item
A mixture of meal or bran and water fed to animals.
@item
-A mess; trouble. [Obs.] --Beau. & Fl.
+A mess; trouble. [Obs.] --Beau.@: & Fl.
@end enumerate
@end quotation
@noindent
If you omit the space before the path, then 4.2@sc{bsd} based systems
-(such as Sequent DYNIX) will ignore the line, because they interpret
+(such as DYNIX) will ignore the line, because they interpret
@samp{#! /} as a 4-byte magic number. Some old systems have quite
small limits on the length of the @samp{#!} line too, for instance 32
bytes (not including the newline) on SunOS 4.
@cindex Ash
@command{ash} is often used on @sc{gnu}/Linux and @sc{bsd} systems as a
light-weight Bourne-compatible shell. Ash 0.2 has some bugs that are
-fixed in the 0.3.x series, but portable shell scripts should workaround
+fixed in the 0.3.x series, but portable shell scripts should work around
them, since version 0.2 is still shipped with many @sc{gnu}/Linux
distributions.
@cindex Bash
To detect whether you are running @command{bash}, test if
@code{BASH_VERSION} is set. To disable its extensions and require
-@sc{posix} compatibility, run @samp{set -o posix}. @xref{Bash POSIX
+@sc{posix} compatibility, run @samp{set -o posix}. @xref{Bash POSIX
Mode,, Bash @sc{posix} Mode, bash, The GNU Bash Reference Manual}, for
details.
To detect whether you are running @command{zsh}, test if
@code{ZSH_VERSION} is set. By default @command{zsh} is @emph{not}
compatible with the Bourne shell: you have to run @samp{emulate sh} and
-set @code{NULLCMD} to @samp{:}. @xref{Compatibility,, Compatibility,
+set @code{NULLCMD} to @samp{:}. @xref{Compatibility,, Compatibility,
zsh, The Z Shell Manual}, for details.
Zsh 3.0.8 is the native @command{/bin/sh} on Mac OS X 10.0.3.
@item Invalid characters
Some characters are invalid in @sc{dos} filenames, and should therefore
-be avoided. In a @sc{lfn} environment, these are @samp{/}, @samp{\},
+be avoided. In a @sc{lfn} environment, these are @samp{/}, @samp{\},
@samp{?}, @samp{*}, @samp{:}, @samp{<}, @samp{>}, @samp{|} and @samp{"}.
In a @sc{sfn} environment, other characters are also invalid. These
include @samp{+}, @samp{,}, @samp{[} and @samp{]}.
@section Shell Substitutions
Contrary to a persistent urban legend, the Bourne shell does not
-systematically split variables and backquoted expressions, in particular
+systematically split variables and back-quoted expressions, in particular
on the right-hand side of assignments and in the argument of @code{case}.
For instance, the following code:
since not all shells properly understand @code{"`@dots{}"@dots{}"@dots{}`"}.
Worse yet, not all shells understand @code{"`@dots{}\"@dots{}\"@dots{}`"}
the same way. There is just no portable way to use double-quoted
-strings inside double-quoted backquoted expressions (pfew!).
+strings inside double-quoted back-quoted expressions (pfew!).
@table @code
@item $@@
@example
zsh $ @kbd{emulate sh}
-zsh $ @kbd{for i in "$@"; do echo $i; done}
+zsh $ @kbd{for i in "$@@"; do echo $i; done}
Hello World
!
zsh $ @kbd{for i in $@{1+"$@@"@}; do echo $i; done}
@noindent
will set @var{var} to @samp{M-yM-uM-,M-yM-aM-a}, i.e., the 8th bit of
-each char will be set. You won't observe the phenomenon using a simple
+each char will be set. You won't observe the phenomenon using a simple
@samp{echo $var} since apparently the shell resets the 8th bit when it
expands $var. Here are two means to make this shell confess its sins:
@node Limitations of Builtins
@section Limitations of Shell Builtins
-No, no, we are serious: some shells do have limitations! :)
+No, no, we are serious: some shells do have limitations! :)
You should always keep in mind that any built-in or command may support
options, and therefore have a very different behavior with arguments
@samp{echo}.
Don't expect any option. @xref{Preset Output Variables}, @code{ECHO_N}
-etc. for a means to simulate @option{-c}.
+etc.@: for a means to simulate @option{-c}.
Do not use backslashes in the arguments, as there is no consensus on
their handling. On @samp{echo '\n' | wc -l}, the @command{sh} of
$unset PS1 || PS1='$ '
@end example
-@xref{Special Shell Variables}, for some neutralizing values. Also, see
+@xref{Special Shell Variables}, for some neutralizing values. Also, see
@ref{Limitations of Builtins}, documentation of @command{export}, for
the case of environment variables.
@end table
@quotation
No, under some older flavors of Unix, leading @samp{//} is a special
path name: it refers to a ``super-root'' and is used to access other
-machines' files. Leading @samp{///}, @samp{////}, etc. are equivalent
+machines' files. Leading @samp{///}, @samp{////}, etc.@: are equivalent
to @samp{/}; but leading @samp{//} is special. I think this tradition
started with Apollo Domain/OS, an OS that is still in use on some older
hosts.
replacement @code{grep -E}. To work around this problem, invoke
@code{AC_PROG_EGREP} and then use @code{$EGREP}.
-The empty alternative is not portable, use @samp{?} instead. For
+The empty alternative is not portable, use @samp{?} instead. For
instance with Digital Unix v5.0:
@example
unfortunately this behaves exactly as the original expression, see the
@samp{@command{expr} (@samp{:})} entry for more information.
-Older @command{expr} implementations (e.g. SunOS 4 @command{expr} and
+Older @command{expr} implementations (e.g., SunOS 4 @command{expr} and
Solaris 8 @command{/usr/ucb/expr}) have a silly length limit that causes
@command{expr} to fail if the matched substring is longer than 120
bytes. In this case, you might want to fall back on @samp{echo|sed} if
@noindent
will output @samp{a} on most hosts, but @samp{aa} on @sc{qnx} 4.25. A
-simple work around consists in testing @command{expr} and use a variable
+simple workaround consists in testing @command{expr} and use a variable
set to @command{expr} or to @command{false} according to the result.
@item @command{find}
@c -----------------
-The option @option{-maxdepth} seems to be GNU specific. Tru64 v5.1,
+The option @option{-maxdepth} seems to be GNU specific. Tru64 v5.1,
NetBSD 1.5 and Solaris 2.5 @command{find} commands do not understand it.
The replacement of @samp{@{@}} is guaranteed only if the argument is
For versions of the DJGPP before 2.04, @command{ln} emulates soft links
for executables by generating a stub that in turn calls the real
program. This feature also works with nonexistent files like in the
-Unix spec. So @samp{ln -s file link} will generate @file{link.exe},
-which will attempt to call @file{file.exe} if run. But this feature only
+Unix spec. So @samp{ln -s file link} will generate @file{link.exe},
+which will attempt to call @file{file.exe} if run. But this feature only
works for executables, so @samp{cp -p} is used instead for these
systems. DJGPP versions 2.04 and later have full symlink support.
Moving directories across mount points is not portable, use @command{cp}
and @command{rm}.
-Moving/Deleting open files isn't portable. The following can't be done
+Moving/Deleting open files isn't portable. The following can't be done
on DOS/WIN32:
@example
Alternation, @samp{\|}, is common but @sc{posix}.2 does not require its
support, so it should be avoided in portable scripts. Solaris 8
-@command{sed} does not support alternation; e.g. @samp{sed '/a\|b/d'}
+@command{sed} does not support alternation; e.g., @samp{sed '/a\|b/d'}
deletes only lines that contain the literal string @samp{a|b}.
Anchors (@samp{^} and @samp{$}) inside groups are not portable.
deleted
@end example
-Why? When processing 1, a matches, therefore sets the t flag, b jumps to
+Why? When processing 1, a matches, therefore sets the t flag, b jumps to
d, and the output is produced. When processing line 2, the t flag is
still set (this is the bug). Line a fails to match, but @command{sed}
is not supposed to clear the t flag when a substitution fails. Line b
@example
VPATH = ../src
.c.o:
- cc -c $< -o $@
+ cc -c $< -o $@@
@end example
@noindent
@example
VPATH = ../src
.c.o:
- cc -c `test -f $< || echo ../src/`$< -o $@
+ cc -c `test -f $< || echo ../src/`$< -o $@@
@end example
This kludge was introduced in Automake in 2000, but the exact context
@end example
Another point worth mentioning is that once GNU @command{make} has
-decided to ignore a @code{VPATH} filename (e.g. it ignored
+decided to ignore a @code{VPATH} filename (e.g., it ignored
@file{../bar.x} in the above example) it will continue to ignore it when
the target occurs as a prerequisite of another rule.
@var{file} and @var{template} may be @samp{-} in which case the standard
output and/or standard input, respectively, is used. If a
@var{template} filename is relative, it is first looked for in the build
-tree, and then in the source tree. @xref{Configuration Actions}, for
+tree, and then in the source tree. @xref{Configuration Actions}, for
more details.
This option and the following ones provide one way for separately
if @file{./acconfig.h} contains the string @samp{@@BOTTOM@@},
@command{autoheader} copies the lines after that line to the end of the
file it generates. Either or both of those strings may be omitted. An
-even older alternate way to produce the same effect in jurasik versions
+even older alternate way to produce the same effect in ancient versions
of Autoconf is to create the files @file{@var{file}.top} (typically
@file{config.h.top}) and/or @file{@var{file}.bot} in the current
directory. If they exist, @command{autoheader} copies them to the
@defmac AC_DYNIX_SEQ
@acindex DYNIX_SEQ
-If on Dynix/PTX (Sequent @sc{unix}), add @option{-lseq} to output variable
+If on DYNIX/ptx, add @option{-lseq} to output variable
@code{LIBS}. This macro used to be defined as
@example
@acindex SYS_RESTARTABLE_SYSCALLS
@cvindex HAVE_RESTARTABLE_SYSCALLS
If the system automatically restarts a system call that is interrupted
-by a signal, define @code{HAVE_RESTARTABLE_SYSCALLS}. This macro does
+by a signal, define @code{HAVE_RESTARTABLE_SYSCALLS}. This macro does
not check if system calls are restarted in general--it tests whether a
signal handler installed with @code{signal} (but not @code{sigaction})
-causes system calls to be restarted. It does not test if system calls
+causes system calls to be restarted. It does not test if system calls
can be restarted when interrupted by signals that have no handler.
These days portable programs should use @code{sigaction} with
@node AC_LIBOBJ vs LIBOBJS
-@subsection @code{AC_LIBOBJ} vs. @code{LIBOBJS}
+@subsection @code{AC_LIBOBJ} vs.@: @code{LIBOBJS}
Up to Autoconf 2.13, the replacement of functions was triggered via the
variable @code{LIBOBJS}. Since Autoconf 2.50, the macro
@defmac AC_CONFIG_TESTDIR (@var{directory}, @dvar{test-path, @var{directory}})
@acindex CONFIG_TESTDIR
An Autotest test suite is to be configured in @var{directory}. This
-macro requires the instanciation of @file{@var{directory}/atconfig} from
+macro requires the instantiation of @file{@var{directory}/atconfig} from
@file{@var{directory}/atconfig.in}, and sets the default
@code{AUTOTEST_PATH} to @var{test-path} (@pxref{testsuite Invocation}).
@end defmac
the @href{http://www.gnu.org/software/ac-archive/, Autoconf Macro
Archive}.
-This solution is not conformant with the GNU Coding Standards.
+This solution does not conform to the GNU Coding Standards.
@item
Note that all the previous solutions hard wire the absolute path to
projects / thirdparty / autoconf.git / commitdiff
