posix/getopt.h

   1 /* Declarations for getopt.
   2    Copyright (C) 1989-2015 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, see
  17    <http://www.gnu.org/licenses/>.  */
  18
  19 #ifndef _GETOPT_H
  20
  21 #ifndef __need_getopt
  22 # define _GETOPT_H 1
  23 #endif
  24
  25 /* If __GNU_LIBRARY__ is not already defined, either we are being used
  26    standalone, or this is the first header included in the source file.
  27    If we are being used with glibc, we need to include <features.h>, but
  28    that does not exist if we are standalone.  So: if __GNU_LIBRARY__ is
  29    not defined, include <ctype.h>, which will pull in <features.h> for us
  30    if it's from glibc.  (Why ctype.h?  It's guaranteed to exist and it
  31    doesn't flood the namespace with stuff the way some other headers do.)  */
  32 #if !defined __GNU_LIBRARY__
  33 # include <ctype.h>
  34 #endif
  35
  36 #ifndef __THROW
  37 # ifndef __GNUC_PREREQ
  38 #  define __GNUC_PREREQ(maj, min) (0)
  39 # endif
  40 # if defined __cplusplus && __GNUC_PREREQ (2,8)
  41 #  define __THROW       throw ()
  42 # else
  43 #  define __THROW
  44 # endif
  45 #endif
  46
  47 #ifdef  __cplusplus
  48 extern "C" {
  49 #endif
  50
  51 /* For communication from `getopt' to the caller.
  52    When `getopt' finds an option that takes an argument,
  53    the argument value is returned here.
  54    Also, when `ordering' is RETURN_IN_ORDER,
  55    each non-option ARGV-element is returned here.  */
  56
  57 extern char *optarg;
  58
  59 /* Index in ARGV of the next element to be scanned.
  60    This is used for communication to and from the caller
  61    and for communication between successive calls to `getopt'.
  62
  63    On entry to `getopt', zero means this is the first call; initialize.
  64
  65    When `getopt' returns -1, this is the index of the first of the
  66    non-option elements that the caller should itself scan.
  67
  68    Otherwise, `optind' communicates from one call to the next
  69    how much of ARGV has been scanned so far.  */
  70
  71 extern int optind;
  72
  73 /* Callers store zero here to inhibit the error message `getopt' prints
  74    for unrecognized options.  */
  75
  76 extern int opterr;
  77
  78 /* Set to an option character which was unrecognized.  */
  79
  80 extern int optopt;
  81
  82 #ifndef __need_getopt
  83 /* Describe the long-named options requested by the application.
  84    The LONG_OPTIONS argument to getopt_long or getopt_long_only is a vector
  85    of `struct option' terminated by an element containing a name which is
  86    zero.
  87
  88    The field `has_arg' is:
  89    no_argument          (or 0) if the option does not take an argument,
  90    required_argument    (or 1) if the option requires an argument,
  91    optional_argument    (or 2) if the option takes an optional argument.
  92
  93    If the field `flag' is not NULL, it points to a variable that is set
  94    to the value given in the field `val' when the option is found, but
  95    left unchanged if the option is not found.
  96
  97    To have a long-named option do something other than set an `int' to
  98    a compiled-in constant, such as set a value from `optarg', set the
  99    option's `flag' field to zero and its `val' field to a nonzero
 100    value (the equivalent single-letter option character, if there is
 101    one).  For long options that have a zero `flag' field, `getopt'
 102    returns the contents of the `val' field.  */
 103
 104 struct option
 105 {
 106   const char *name;
 107   /* has_arg can't be an enum because some compilers complain about
 108      type mismatches in all the code that assumes it is an int.  */
 109   int has_arg;
 110   int *flag;
 111   int val;
 112 };
 113
 114 /* Names for the values of the `has_arg' field of `struct option'.  */
 115
 116 # define no_argument            0
 117 # define required_argument      1
 118 # define optional_argument      2
 119 #endif  /* need getopt */
 120
 121
 122 /* Get definitions and prototypes for functions to process the
 123    arguments in ARGV (ARGC of them, minus the program name) for
 124    options given in OPTS.
 125
 126    Return the option character from OPTS just read.  Return -1 when
 127    there are no more options.  For unrecognized options, or options
 128    missing arguments, `optopt' is set to the option letter, and '?' is
 129    returned.
 130
 131    The OPTS string is a list of characters which are recognized option
 132    letters, optionally followed by colons, specifying that that letter
 133    takes an argument, to be placed in `optarg'.
 134
 135    If a letter in OPTS is followed by two colons, its argument is
 136    optional.  This behavior is specific to the GNU `getopt'.
 137
 138    The argument `--' causes premature termination of argument
 139    scanning, explicitly telling `getopt' that there are no more
 140    options.
 141
 142    If OPTS begins with `--', then non-option arguments are treated as
 143    arguments to the option '\0'.  This behavior is specific to the GNU
 144    `getopt'.  */
 145
 146 #ifdef __GNU_LIBRARY__
 147 /* Many other libraries have conflicting prototypes for getopt, with
 148    differences in the consts, in stdlib.h.  To avoid compilation
 149    errors, only prototype getopt for the GNU C library.  */
 150 extern int getopt (int ___argc, char *const *___argv, const char *__shortopts)
 151        __THROW;
 152
 153 # if defined __need_getopt && defined __USE_POSIX2 \
 154   && !defined __USE_POSIX_IMPLICITLY && !defined __USE_GNU
 155 /* The GNU getopt has more functionality than the standard version.  The
 156    additional functionality can be disable at runtime.  This redirection
 157    helps to also do this at runtime.  */
 158 #  ifdef __REDIRECT
 159   extern int __REDIRECT_NTH (getopt, (int ___argc, char *const *___argv,
 160                                       const char *__shortopts),
 161                              __posix_getopt);
 162 #  else
 163 extern int __posix_getopt (int ___argc, char *const *___argv,
 164                            const char *__shortopts) __THROW;
 165 #   define getopt __posix_getopt
 166 #  endif
 167 # endif
 168 #else /* not __GNU_LIBRARY__ */
 169 extern int getopt ();
 170 #endif /* __GNU_LIBRARY__ */
 171
 172 #ifndef __need_getopt
 173 extern int getopt_long (int ___argc, char *const *___argv,
 174                         const char *__shortopts,
 175                         const struct option *__longopts, int *__longind)
 176        __THROW;
 177 extern int getopt_long_only (int ___argc, char *const *___argv,
 178                              const char *__shortopts,
 179                              const struct option *__longopts, int *__longind)
 180        __THROW;
 181
 182 #endif
 183
 184 #ifdef  __cplusplus
 185 }
 186 #endif
 187
 188 /* Make sure we later can get all the definitions and declarations.  */
 189 #undef __need_getopt
 190
 191 #endif /* getopt.h */