posix/getopt.h

   1 /* Declarations for getopt.
   2    Copyright (C) 1989-1994,1996-1999,2001,2003,2004,2009,2010
   3    Free Software Foundation, Inc.
   4    This file is part of the GNU C Library.
   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, write to the Free
  18    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  19    02111-1307 USA.  */
  20
  21 #ifndef _GETOPT_H
  22
  23 #ifndef __need_getopt
  24 # define _GETOPT_H 1
  25 #endif
  26
  27 /* If __GNU_LIBRARY__ is not already defined, either we are being used
  28    standalone, or this is the first header included in the source file.
  29    If we are being used with glibc, we need to include <features.h>, but
  30    that does not exist if we are standalone.  So: if __GNU_LIBRARY__ is
  31    not defined, include <ctype.h>, which will pull in <features.h> for us
  32    if it's from glibc.  (Why ctype.h?  It's guaranteed to exist and it
  33    doesn't flood the namespace with stuff the way some other headers do.)  */
  34 #if !defined __GNU_LIBRARY__
  35 # include <ctype.h>
  36 #endif
  37
  38 #ifndef __THROW
  39 # ifndef __GNUC_PREREQ
  40 #  define __GNUC_PREREQ(maj, min) (0)
  41 # endif
  42 # if defined __cplusplus && __GNUC_PREREQ (2,8)
  43 #  define __THROW       throw ()
  44 # else
  45 #  define __THROW
  46 # endif
  47 #endif
  48
  49 #ifdef  __cplusplus
  50 extern "C" {
  51 #endif
  52
  53 /* For communication from `getopt' to the caller.
  54    When `getopt' finds an option that takes an argument,
  55    the argument value is returned here.
  56    Also, when `ordering' is RETURN_IN_ORDER,
  57    each non-option ARGV-element is returned here.  */
  58
  59 extern char *optarg;
  60
  61 /* Index in ARGV of the next element to be scanned.
  62    This is used for communication to and from the caller
  63    and for communication between successive calls to `getopt'.
  64
  65    On entry to `getopt', zero means this is the first call; initialize.
  66
  67    When `getopt' returns -1, this is the index of the first of the
  68    non-option elements that the caller should itself scan.
  69
  70    Otherwise, `optind' communicates from one call to the next
  71    how much of ARGV has been scanned so far.  */
  72
  73 extern int optind;
  74
  75 /* Callers store zero here to inhibit the error message `getopt' prints
  76    for unrecognized options.  */
  77
  78 extern int opterr;
  79
  80 /* Set to an option character which was unrecognized.  */
  81
  82 extern int optopt;
  83
  84 #ifndef __need_getopt
  85 /* Describe the long-named options requested by the application.
  86    The LONG_OPTIONS argument to getopt_long or getopt_long_only is a vector
  87    of `struct option' terminated by an element containing a name which is
  88    zero.
  89
  90    The field `has_arg' is:
  91    no_argument          (or 0) if the option does not take an argument,
  92    required_argument    (or 1) if the option requires an argument,
  93    optional_argument    (or 2) if the option takes an optional argument.
  94
  95    If the field `flag' is not NULL, it points to a variable that is set
  96    to the value given in the field `val' when the option is found, but
  97    left unchanged if the option is not found.
  98
  99    To have a long-named option do something other than set an `int' to
 100    a compiled-in constant, such as set a value from `optarg', set the
 101    option's `flag' field to zero and its `val' field to a nonzero
 102    value (the equivalent single-letter option character, if there is
 103    one).  For long options that have a zero `flag' field, `getopt'
 104    returns the contents of the `val' field.  */
 105
 106 struct option
 107 {
 108   const char *name;
 109   /* has_arg can't be an enum because some compilers complain about
 110      type mismatches in all the code that assumes it is an int.  */
 111   int has_arg;
 112   int *flag;
 113   int val;
 114 };
 115
 116 /* Names for the values of the `has_arg' field of `struct option'.  */
 117
 118 # define no_argument            0
 119 # define required_argument      1
 120 # define optional_argument      2
 121 #endif  /* need getopt */
 122
 123
 124 /* Get definitions and prototypes for functions to process the
 125    arguments in ARGV (ARGC of them, minus the program name) for
 126    options given in OPTS.
 127
 128    Return the option character from OPTS just read.  Return -1 when
 129    there are no more options.  For unrecognized options, or options
 130    missing arguments, `optopt' is set to the option letter, and '?' is
 131    returned.
 132
 133    The OPTS string is a list of characters which are recognized option
 134    letters, optionally followed by colons, specifying that that letter
 135    takes an argument, to be placed in `optarg'.
 136
 137    If a letter in OPTS is followed by two colons, its argument is
 138    optional.  This behavior is specific to the GNU `getopt'.
 139
 140    The argument `--' causes premature termination of argument
 141    scanning, explicitly telling `getopt' that there are no more
 142    options.
 143
 144    If OPTS begins with `--', then non-option arguments are treated as
 145    arguments to the option '\0'.  This behavior is specific to the GNU
 146    `getopt'.  */
 147
 148 #ifdef __GNU_LIBRARY__
 149 /* Many other libraries have conflicting prototypes for getopt, with
 150    differences in the consts, in stdlib.h.  To avoid compilation
 151    errors, only prototype getopt for the GNU C library.  */
 152 extern int getopt (int ___argc, char *const *___argv, const char *__shortopts)
 153        __THROW;
 154
 155 # if defined __need_getopt && defined __USE_POSIX2 \
 156   && !defined __USE_POSIX_IMPLICITLY && !defined __USE_GNU
 157 /* The GNU getopt has more functionality than the standard version.  The
 158    additional functionality can be disable at runtime.  This redirection
 159    helps to also do this at runtime.  */
 160 #  ifdef __REDIRECT
 161   extern int __REDIRECT_NTH (getopt, (int ___argc, char *const *___argv,
 162                                       const char *__shortopts),
 163                              __posix_getopt);
 164 #  else
 165 extern int __posix_getopt (int ___argc, char *const *___argv,
 166                            const char *__shortopts) __THROW;
 167 #   define getopt __posix_getopt
 168 #  endif
 169 # endif
 170 #else /* not __GNU_LIBRARY__ */
 171 extern int getopt ();
 172 #endif /* __GNU_LIBRARY__ */
 173
 174 #ifndef __need_getopt
 175 extern int getopt_long (int ___argc, char *const *___argv,
 176                         const char *__shortopts,
 177                         const struct option *__longopts, int *__longind)
 178        __THROW;
 179 extern int getopt_long_only (int ___argc, char *const *___argv,
 180                              const char *__shortopts,
 181                              const struct option *__longopts, int *__longind)
 182        __THROW;
 183
 184 #endif
 185
 186 #ifdef  __cplusplus
 187 }
 188 #endif
 189
 190 /* Make sure we later can get all the definitions and declarations.  */
 191 #undef __need_getopt
 192
 193 #endif /* getopt.h */