examples/loadables/README

   1 Some examples of ready-to-dynamic-load builtins.  Most of the
   2 examples given are reimplementations of standard commands whose
   3 execution time is dominated by process startup time.  The
   4 exceptions are sleep, which allows you to sleep for fractions
   5 of a second, finfo, which provides access to the rest of the
   6 elements of the `stat' structure that `test' doesn't let you
   7 see, and pushd/popd/dirs, which allows you to compile them out
   8 of the shell.
   9
  10 All of the new builtins in ksh93 that bash didn't already have
  11 are included here, as is the ksh `print' builtin.
  12
  13 The configure script in the top-level source directory uses the
  14 support/shobj-conf script to set the right values in the Makefile,
  15 so you should not need to change the Makefile.  If your system
  16 is not supported by support/shobj-conf, and it has the necessary
  17 facilities for building shared objects and support for the
  18 dlopen/dlsyn/dlclose/dlerror family of functions, please make
  19 the necessary changes to support/shobj-conf and send the changes
  20 to bash-maintainers@gnu.org.
  21
  22 Loadable builtins are loaded into a running shell with
  23
  24         enable -f filename builtin-name
  25
  26 enable uses a simple reference-counting scheme to avoid unloading a
  27 shared object that implements more than one loadable builtin before
  28 all loadable builtins implemented in the object are removed.
  29
  30 Many of the details needed by builtin writers are found in hello.c,
  31 the canonical example.  There is no real `builtin writers' programming
  32 guide'.  The file template.c provides a template to use for creating
  33 new loadable builtins.
  34
  35 basename.c      Return non-directory portion of pathname.
  36 cat.c           cat(1) replacement with no options - the way cat was intended.
  37 dirname.c       Return directory portion of pathname.
  38 finfo.c         Print file info.
  39 head.c          Copy first part of files.
  40 hello.c         Obligatory "Hello World" / sample loadable.
  41 id.c            POSIX.2 user identity.
  42 ln.c            Make links.
  43 loadables.h     Start at a file loadable builtins can include for shell definitions
  44 logname.c       Print login name of current user.
  45 Makefile.in     Simple makefile for the sample loadable builtins.
  46 mkdir.c         Make directories.
  47 mypid.c         Add $MYPID variable, demonstrate use of unload hook function
  48 necho.c         echo without options or argument interpretation.
  49 pathchk.c       Check pathnames for validity and portability.
  50 print.c         Loadable ksh-93 style print builtin.
  51 printenv.c      Minimal builtin clone of BSD printenv(1).
  52 push.c          Anyone remember TOPS-20?
  53 README          README
  54 realpath.c      Canonicalize pathnames, resolving symlinks.
  55 rmdir.c         Remove directory.
  56 sleep.c         sleep for fractions of a second.
  57 strftime.c      Loadable builtin interface to strftime(3).
  58 sync.c          Sync the disks by forcing pending filesystem writes to complete.
  59 tee.c           Duplicate standard input.
  60 template.c      Example template for loadable builtin.
  61 truefalse.c     True and false builtins.
  62 tty.c           Return terminal name.
  63 uname.c         Print system information.
  64 unlink.c        Remove a directory entry.
  65 whoami.c        Print out username of current user.