include/getopt.h

   1 /* Declarations for getopt.
   2    Copyright (C) 1989-2024 Free Software Foundation, Inc.
   3
   4    NOTE: The canonical source of this file is maintained with the GNU C Library.
   5    Bugs can be reported to bug-glibc@gnu.org.
   6
   7    This program is free software; you can redistribute it and/or modify it
   8    under the terms of the GNU General Public License as published by the
   9    Free Software Foundation; either version 2, or (at your option) any
  10    later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program; if not, write to the Free Software
  19    Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, MA 02110-1301,
  20    USA.  */
  21
  22 #ifndef _GETOPT_H
  23 #define _GETOPT_H 1
  24
  25 #ifdef  __cplusplus
  26 extern "C" {
  27 #endif
  28
  29 /* For communication from `getopt' to the caller.
  30    When `getopt' finds an option that takes an argument,
  31    the argument value is returned here.
  32    Also, when `ordering' is RETURN_IN_ORDER,
  33    each non-option ARGV-element is returned here.  */
  34
  35 extern char *optarg;
  36
  37 /* Index in ARGV of the next element to be scanned.
  38    This is used for communication to and from the caller
  39    and for communication between successive calls to `getopt'.
  40
  41    On entry to `getopt', zero means this is the first call; initialize.
  42
  43    When `getopt' returns -1, this is the index of the first of the
  44    non-option elements that the caller should itself scan.
  45
  46    Otherwise, `optind' communicates from one call to the next
  47    how much of ARGV has been scanned so far.  */
  48
  49 extern int optind;
  50
  51 /* Callers store zero here to inhibit the error message `getopt' prints
  52    for unrecognized options.  */
  53
  54 extern int opterr;
  55
  56 /* Set to an option character which was unrecognized.  */
  57
  58 extern int optopt;
  59
  60 /* Describe the long-named options requested by the application.
  61    The LONG_OPTIONS argument to getopt_long or getopt_long_only is a vector
  62    of `struct option' terminated by an element containing a name which is
  63    zero.
  64
  65    The field `has_arg' is:
  66    no_argument          (or 0) if the option does not take an argument,
  67    required_argument    (or 1) if the option requires an argument,
  68    optional_argument    (or 2) if the option takes an optional argument.
  69
  70    If the field `flag' is not NULL, it points to a variable that is set
  71    to the value given in the field `val' when the option is found, but
  72    left unchanged if the option is not found.
  73
  74    To have a long-named option do something other than set an `int' to
  75    a compiled-in constant, such as set a value from `optarg', set the
  76    option's `flag' field to zero and its `val' field to a nonzero
  77    value (the equivalent single-letter option character, if there is
  78    one).  For long options that have a zero `flag' field, `getopt'
  79    returns the contents of the `val' field.  */
  80
  81 struct option
  82 {
  83 #if defined (__STDC__) && __STDC__
  84   const char *name;
  85 #else
  86   char *name;
  87 #endif
  88   /* has_arg can't be an enum because some compilers complain about
  89      type mismatches in all the code that assumes it is an int.  */
  90   int has_arg;
  91   int *flag;
  92   int val;
  93 };
  94
  95 /* Names for the values of the `has_arg' field of `struct option'.  */
  96
  97 #define no_argument             0
  98 #define required_argument       1
  99 #define optional_argument       2
 100
 101 #if defined (__STDC__) && __STDC__
 102 /* HAVE_DECL_* is a three-state macro: undefined, 0 or 1.  If it is
 103    undefined, we haven't run the autoconf check so provide the
 104    declaration without arguments.  If it is 0, we checked and failed
 105    to find the declaration so provide a fully prototyped one.  If it
 106    is 1, we found it so don't provide any declaration at all.  */
 107 #if !HAVE_DECL_GETOPT
 108 #if defined (__GNU_LIBRARY__) || defined (HAVE_DECL_GETOPT)
 109 /* Many other libraries have conflicting prototypes for getopt, with
 110    differences in the consts, in unistd.h.  To avoid compilation
 111    errors, only prototype getopt for the GNU C library.  */
 112 extern int getopt (int argc, char *const *argv, const char *shortopts);
 113 #else
 114 #ifndef __cplusplus
 115 extern int getopt ();
 116 #endif /* __cplusplus */
 117 #endif
 118 #endif /* !HAVE_DECL_GETOPT */
 119
 120 extern int getopt_long (int argc, char *const *argv, const char *shortopts,
 121                         const struct option *longopts, int *longind);
 122 extern int getopt_long_only (int argc, char *const *argv,
 123                              const char *shortopts,
 124                              const struct option *longopts, int *longind);
 125
 126 /* Internal only.  Users should not call this directly.  */
 127 extern int _getopt_internal (int argc, char *const *argv,
 128                              const char *shortopts,
 129                              const struct option *longopts, int *longind,
 130                              int long_only);
 131 #else /* not __STDC__ */
 132 extern int getopt ();
 133 extern int getopt_long ();
 134 extern int getopt_long_only ();
 135
 136 extern int _getopt_internal ();
 137 #endif /* __STDC__ */
 138
 139 #ifdef  __cplusplus
 140 }
 141 #endif
 142
 143 #endif /* getopt.h */