kc3-lang/gnulib/doc/posix-functions/getopt.texi

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• Hash : c0c5acfb
  Author :
  Date : 2009-11-27T17:47:21
  

  getopt-gnu: flush out another BSD bug
  
  POSIX requires 'echo foo > bar; m4 -Dfoo=1 bar -Dfoo=2 bar' to
  output '1' then '2'.  To achieve this, m4 relies on the GNU
  getopt{,_long} extension of a leading '-'.  However, BSD getopt
  fails to honor this extension when POSIXLY_CORRECT.
  
  Also, BSD getopt fails to reparse POSIXLY_CORRECT from the
  environment even when a reset is requested (whether by
  optreset=1 or by optind=0).
  
  * m4/getopt.m4 (gl_GETOPT_CHECK_HEADERS): Test for the bug.
  * tests/test-getopt.c (main): Check POSIXLY_CORRECT first, to
  flush out BSD bug.
  * tests/test-getopt.h (test_getopt): End lists with NULL.
  * tests/test-getopt_long.h (test_getopt_long): Likewise.
  (test_getopt_long_posix): Enhance test.
  * modules/getopt-posix-tests (Depends-on): Add stdbool.
  * doc/glibc-functions/getopt_long.texi (getopt_long): Mention
  getopt-gnu.
  * doc/glibc-functions/getopt_long_only.texi (getopt_long_only):
  Likewise.
  
  Signed-off-by: Eric Blake <ebb9@byu.net>
  

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• doc/posix-functions/getopt.texi

• @node getopt
  @section @code{getopt}
  @findex getopt
  
  POSIX specification: @url{http://www.opengroup.org/onlinepubs/9699919799/functions/getopt.html}
  
  Gnulib module: getopt-posix or getopt-gnu
  
  The module @code{getopt-gnu} has support for ``long options'' and for
  ``options that take optional arguments''.  Compared to the API defined by POSIX,
  it adds a header file @code{<getopt.h>} and a function @code{getopt_long}.
  
  Portability problems fixed by either Gnulib module @code{getopt-posix} or @code{getopt-gnu}:
  @itemize
  @item
  The @code{getopt} function keeps some internal state that cannot be explicitly
  reset on some platforms:
  mingw.
  @end itemize
  
  Portability problems fixed by Gnulib module @code{getopt-gnu}:
  @itemize
  @item
  The function @code{getopt} does not support the @samp{+} flag in the options
  string on some platforms:
  MacOS X 10.5, AIX 5.2, HP-UX 11, IRIX 6.5, OSF/1 5.1, Solaris 10.
  @item
  The function @code{getopt} does not obey the @samp{-} flag in the options
  string when @env{POSIXLY_CORRECT} is set on some platforms:
  Cygwin 1.7.0.
  @item
  The function @code{getopt} does not support options with optional arguments
  on some platforms:
  MacOS X 10.5, OpenBSD 4.0, AIX 5.2, HP-UX 11, IRIX 6.5, OSF/1 5.1,
  Solaris 10, Cygwin 1.5.x.
  @item
  The function @code{getopt_long} is missing on some platforms:
  AIX 5.1, HP-UX 11, IRIX 6.5, OSF/1 5.1, Solaris 9, Interix 3.5.
  @item
  The function @code{getopt_long_only} is missing on some platforms:
  MacOS X 10.3, FreeBSD 5.2.1, NetBSD 3.0, AIX 5.1, HP-UX 11, IRIX 6.5,
  OSF/1 5.1, Solaris 9, mingw, Interix 3.5.
  @end itemize
  
  Portability problems not fixed by Gnulib:
  @itemize
  @item
  The default behavior of the glibc implementation of @code{getopt} allows
  mixing option and non-option arguments on the command line in any order.
  Other implementations, such as the one in Cygwin, enforce strict POSIX
  compliance: they require that the option arguments precede the non-option
  arguments.  This is something to watch out in your program's
  testsuite.
  @item
  The glibc implementation allows a complete reset of the environment,
  including re-checking for @env{POSIXLY_CORRECT}, by setting
  @code{optind} to 0.  Other implementations provide @code{optreset},
  causing a reset by setting it non-zero, although it does not
  necessarily re-read @env{POSIXLY_CORRECT}.
  @end itemize
  

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