gl/getopt-core.h

   1 /* Declarations for getopt (basic, portable features only).
   2    Copyright (C) 1989-2024 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library and is also part of gnulib.
   4    Patches to this file should be submitted to both projects.
   5
   6    The GNU C Library is free software; you can redistribute it and/or
   7    modify it under the terms of the GNU Lesser General Public
   8    License as published by the Free Software Foundation; either
   9    version 2.1 of the License, or (at your option) any later version.
  10
  11    The GNU C Library is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14    Lesser General Public License for more details.
  15
  16    You should have received a copy of the GNU Lesser General Public
  17    License along with the GNU C Library; if not, see
  18    <https://www.gnu.org/licenses/>.  */
  19
  20 #ifndef _GETOPT_CORE_H
  21 #define _GETOPT_CORE_H 1
  22
  23 /* This header should not be used directly; include getopt.h or
  24    unistd.h instead.  Unlike most bits headers, it does not have
  25    a protective #error, because the guard macro for getopt.h in
  26    gnulib is not fixed.  */
  27
  28 __BEGIN_DECLS
  29
  30 /* For communication from 'getopt' to the caller.
  31    When 'getopt' finds an option that takes an argument,
  32    the argument value is returned here.
  33    Also, when 'ordering' is RETURN_IN_ORDER,
  34    each non-option ARGV-element is returned here.  */
  35
  36 extern char *optarg;
  37
  38 /* Index in ARGV of the next element to be scanned.
  39    This is used for communication to and from the caller
  40    and for communication between successive calls to 'getopt'.
  41
  42    On entry to 'getopt', zero means this is the first call; initialize.
  43
  44    When 'getopt' returns -1, this is the index of the first of the
  45    non-option elements that the caller should itself scan.
  46
  47    Otherwise, 'optind' communicates from one call to the next
  48    how much of ARGV has been scanned so far.  */
  49
  50 extern int optind;
  51
  52 /* Callers store zero here to inhibit the error message 'getopt' prints
  53    for unrecognized options.  */
  54
  55 extern int opterr;
  56
  57 /* Set to an option character which was unrecognized.  */
  58
  59 extern int optopt;
  60
  61 /* Get definitions and prototypes for functions to process the
  62    arguments in ARGV (ARGC of them, minus the program name) for
  63    options given in OPTS.
  64
  65    Return the option character from OPTS just read.  Return -1 when
  66    there are no more options.  For unrecognized options, or options
  67    missing arguments, 'optopt' is set to the option letter, and '?' is
  68    returned.
  69
  70    The OPTS string is a list of characters which are recognized option
  71    letters, optionally followed by colons, specifying that that letter
  72    takes an argument, to be placed in 'optarg'.
  73
  74    If a letter in OPTS is followed by two colons, its argument is
  75    optional.  This behavior is specific to the GNU 'getopt'.
  76
  77    The argument '--' causes premature termination of argument
  78    scanning, explicitly telling 'getopt' that there are no more
  79    options.
  80
  81    If OPTS begins with '-', then non-option arguments are treated as
  82    arguments to the option '\1'.  This behavior is specific to the GNU
  83    'getopt'.  If OPTS begins with '+', or POSIXLY_CORRECT is set in
  84    the environment, then do not permute arguments.
  85
  86    For standards compliance, the 'argv' argument has the type
  87    char *const *, but this is inaccurate; if argument permutation is
  88    enabled, the argv array (not the strings it points to) must be
  89    writable.  */
  90
  91 extern int getopt (int ___argc, char *const *___argv, const char *__shortopts)
  92        __THROW _GL_ARG_NONNULL ((2, 3));
  93
  94 __END_DECLS
  95
  96 #endif /* _GETOPT_CORE_H */