lib/getopt-core.h

   1 /* SPDX-License-Identifier: LGPL-2.1-or-later */
   2
   3 /* Declarations for getopt (basic, portable features only).
   4    Copyright (C) 1989-2023 Free Software Foundation, Inc.
   5    This file is part of the GNU C Library and is also part of gnulib.
   6    Patches to this file should be submitted to both projects.
   7
   8    The GNU C Library is free software; you can redistribute it and/or
   9    modify it under the terms of the GNU Lesser General Public
  10    License as published by the Free Software Foundation; either
  11    version 2.1 of the License, or (at your option) any later version.
  12
  13    The GNU C Library is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16    Lesser General Public License for more details.
  17
  18    You should have received a copy of the GNU Lesser General Public
  19    License along with the GNU C Library; if not, see
  20    <https://www.gnu.org/licenses/>.  */
  21
  22 #ifndef _GETOPT_CORE_H
  23 #define _GETOPT_CORE_H 1
  24
  25 /* This header should not be used directly; include getopt.h or
  26    unistd.h instead.  Unlike most bits headers, it does not have
  27    a protective #error, because the guard macro for getopt.h in
  28    gnulib is not fixed.  */
  29
  30 __BEGIN_DECLS
  31
  32 /* For communication from 'getopt' to the caller.
  33    When 'getopt' finds an option that takes an argument,
  34    the argument value is returned here.
  35    Also, when 'ordering' is RETURN_IN_ORDER,
  36    each non-option ARGV-element is returned here.  */
  37
  38 extern char *optarg;
  39
  40 /* Index in ARGV of the next element to be scanned.
  41    This is used for communication to and from the caller
  42    and for communication between successive calls to 'getopt'.
  43
  44    On entry to 'getopt', zero means this is the first call; initialize.
  45
  46    When 'getopt' returns -1, this is the index of the first of the
  47    non-option elements that the caller should itself scan.
  48
  49    Otherwise, 'optind' communicates from one call to the next
  50    how much of ARGV has been scanned so far.  */
  51
  52 extern int optind;
  53
  54 /* Callers store zero here to inhibit the error message 'getopt' prints
  55    for unrecognized options.  */
  56
  57 extern int opterr;
  58
  59 /* Set to an option character which was unrecognized.  */
  60
  61 extern int optopt;
  62
  63 /* Get definitions and prototypes for functions to process the
  64    arguments in ARGV (ARGC of them, minus the program name) for
  65    options given in OPTS.
  66
  67    Return the option character from OPTS just read.  Return -1 when
  68    there are no more options.  For unrecognized options, or options
  69    missing arguments, 'optopt' is set to the option letter, and '?' is
  70    returned.
  71
  72    The OPTS string is a list of characters which are recognized option
  73    letters, optionally followed by colons, specifying that that letter
  74    takes an argument, to be placed in 'optarg'.
  75
  76    If a letter in OPTS is followed by two colons, its argument is
  77    optional.  This behavior is specific to the GNU 'getopt'.
  78
  79    The argument '--' causes premature termination of argument
  80    scanning, explicitly telling 'getopt' that there are no more
  81    options.
  82
  83    If OPTS begins with '-', then non-option arguments are treated as
  84    arguments to the option '\1'.  This behavior is specific to the GNU
  85    'getopt'.  If OPTS begins with '+', or POSIXLY_CORRECT is set in
  86    the environment, then do not permute arguments.
  87
  88    For standards compliance, the 'argv' argument has the type
  89    char *const *, but this is inaccurate; if argument permutation is
  90    enabled, the argv array (not the strings it points to) must be
  91    writable.  */
  92
  93 extern int getopt (int ___argc, char *const *___argv, const char *__shortopts)
  94        __THROW _GL_ARG_NONNULL ((2, 3));
  95
  96 __END_DECLS
  97
  98 #endif /* _GETOPT_CORE_H */