examples/getopt/getopt.h

   1 /* Declarations for getopt.
   2    Copyright (C) 1989-1994, 1996-1999, 2001 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, write to the Free
  17    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  18    02111-1307 USA.  */
  19
  20 #ifndef _GETOPT_H
  21
  22 #ifndef __need_getopt
  23 # define _GETOPT_H 1
  24 #endif
  25
  26 /* If __GNU_LIBRARY__ is not already defined, either we are being used
  27    standalone, or this is the first header included in the source file.
  28    If we are being used with glibc, we need to include <features.h>, but
  29    that does not exist if we are standalone.  So: if __GNU_LIBRARY__ is
  30    not defined, include <ctype.h>, which will pull in <features.h> for us
  31    if it's from glibc.  (Why ctype.h?  It's guaranteed to exist and it
  32    doesn't flood the namespace with stuff the way some other headers do.)  */
  33 #if !defined __GNU_LIBRARY__
  34 # include <ctype.h>
  35 #endif
  36
  37 #ifdef  __cplusplus
  38 extern "C" {
  39 #endif
  40
  41 /* For communication from `getopt' to the caller.
  42    When `getopt' finds an option that takes an argument,
  43    the argument value is returned here.
  44    Also, when `ordering' is RETURN_IN_ORDER,
  45    each non-option ARGV-element is returned here.  */
  46
  47 extern char *optarg;
  48
  49 /* Index in ARGV of the next element to be scanned.
  50    This is used for communication to and from the caller
  51    and for communication between successive calls to `getopt'.
  52
  53    On entry to `getopt', zero means this is the first call; initialize.
  54
  55    When `getopt' returns -1, this is the index of the first of the
  56    non-option elements that the caller should itself scan.
  57
  58    Otherwise, `optind' communicates from one call to the next
  59    how much of ARGV has been scanned so far.  */
  60
  61 extern int optind;
  62
  63 /* Callers store zero here to inhibit the error message `getopt' prints
  64    for unrecognized options.  */
  65
  66 extern int opterr;
  67
  68 /* Set to an option character which was unrecognized.  */
  69
  70 extern int optopt;
  71
  72 #ifndef __need_getopt
  73 /* Describe the long-named options requested by the application.
  74    The LONG_OPTIONS argument to getopt_long or getopt_long_only is a vector
  75    of `struct option' terminated by an element containing a name which is
  76    zero.
  77
  78    The field `has_arg' is:
  79    no_argument          (or 0) if the option does not take an argument,
  80    required_argument    (or 1) if the option requires an argument,
  81    optional_argument    (or 2) if the option takes an optional argument.
  82
  83    If the field `flag' is not NULL, it points to a variable that is set
  84    to the value given in the field `val' when the option is found, but
  85    left unchanged if the option is not found.
  86
  87    To have a long-named option do something other than set an `int' to
  88    a compiled-in constant, such as set a value from `optarg', set the
  89    option's `flag' field to zero and its `val' field to a nonzero
  90    value (the equivalent single-letter option character, if there is
  91    one).  For long options that have a zero `flag' field, `getopt'
  92    returns the contents of the `val' field.  */
  93
  94 struct option
  95 {
  96 # if (defined __STDC__ && __STDC__) || defined __cplusplus
  97   const char *name;
  98 # else
  99   char *name;
 100 # endif
 101   /* has_arg can't be an enum because some compilers complain about
 102      type mismatches in all the code that assumes it is an int.  */
 103   int has_arg;
 104   int *flag;
 105   int val;
 106 };
 107
 108 /* Names for the values of the `has_arg' field of `struct option'.  */
 109
 110 # define no_argument            0
 111 # define required_argument      1
 112 # define optional_argument      2
 113 #endif  /* need getopt */
 114
 115
 116 /* Get definitions and prototypes for functions to process the
 117    arguments in ARGV (ARGC of them, minus the program name) for
 118    options given in OPTS.
 119
 120    Return the option character from OPTS just read.  Return -1 when
 121    there are no more options.  For unrecognized options, or options
 122    missing arguments, `optopt' is set to the option letter, and '?' is
 123    returned.
 124
 125    The OPTS string is a list of characters which are recognized option
 126    letters, optionally followed by colons, specifying that that letter
 127    takes an argument, to be placed in `optarg'.
 128
 129    If a letter in OPTS is followed by two colons, its argument is
 130    optional.  This behavior is specific to the GNU `getopt'.
 131
 132    The argument `--' causes premature termination of argument
 133    scanning, explicitly telling `getopt' that there are no more
 134    options.
 135
 136    If OPTS begins with `--', then non-option arguments are treated as
 137    arguments to the option '\0'.  This behavior is specific to the GNU
 138    `getopt'.  */
 139
 140 #if (defined __STDC__ && __STDC__) || defined __cplusplus
 141 # ifdef __GNU_LIBRARY__
 142 /* Many other libraries have conflicting prototypes for getopt, with
 143    differences in the consts, in stdlib.h.  To avoid compilation
 144    errors, only prototype getopt for the GNU C library.  */
 145 extern int getopt (int __argc, char *const *__argv, const char *__shortopts);
 146 # else /* not __GNU_LIBRARY__ */
 147 extern int getopt ();
 148 # endif /* __GNU_LIBRARY__ */
 149
 150 # ifndef __need_getopt
 151 extern int getopt_long (int __argc, char *const *__argv, const char *__shortopts,
 152                         const struct option *__longopts, int *__longind);
 153 extern int getopt_long_only (int __argc, char *const *__argv,
 154                              const char *__shortopts,
 155                              const struct option *__longopts, int *__longind);
 156
 157 /* Internal only.  Users should not call this directly.  */
 158 extern int _getopt_internal (int __argc, char *const *__argv,
 159                              const char *__shortopts,
 160                              const struct option *__longopts, int *__longind,
 161                              int __long_only);
 162 # endif
 163 #else /* not __STDC__ */
 164 extern int getopt ();
 165 # ifndef __need_getopt
 166 extern int getopt_long ();
 167 extern int getopt_long_only ();
 168
 169 extern int _getopt_internal ();
 170 # endif
 171 #endif /* __STDC__ */
 172
 173 #ifdef  __cplusplus
 174 }
 175 #endif
 176
 177 /* Make sure we later can get all the definitions and declarations.  */
 178 #undef __need_getopt
 179
 180 #endif /* getopt.h */