Handle default value
[emacs.git] / lib-src / getopt_.h
blob7cccef3eeea24c5efd8b311795c8fad227b65eea
1 /* Declarations for getopt.
2 Copyright (C) 1989, 1990, 1991, 1992, 1993, 1994, 1996, 1997, 1998, 1999,
3 2001, 2003, 2004, 2005, 2006, 2007 Free Software Foundation, Inc.
4 This file is part of the GNU C Library.
6 This program is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 3, or (at your option)
9 any later version.
11 This program 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
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License along
17 with this program; if not, write to the Free Software Foundation,
18 Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
20 #ifndef _GETOPT_H
22 #ifndef __need_getopt
23 # define _GETOPT_H 1
24 #endif
26 /* Standalone applications should #define __GETOPT_PREFIX to an
27 identifier that prefixes the external functions and variables
28 defined in this header. When this happens, include the
29 headers that might declare getopt so that they will not cause
30 confusion if included after this file. Then systematically rename
31 identifiers so that they do not collide with the system functions
32 and variables. Renaming avoids problems with some compilers and
33 linkers. */
34 #if defined __GETOPT_PREFIX && !defined __need_getopt
35 # include <stdlib.h>
36 # include <stdio.h>
37 # if HAVE_UNISTD_H
38 # include <unistd.h>
39 # endif
40 # undef __need_getopt
41 # undef getopt
42 # undef getopt_long
43 # undef getopt_long_only
44 # undef optarg
45 # undef opterr
46 # undef optind
47 # undef optopt
48 # define __GETOPT_CONCAT(x, y) x ## y
49 # define __GETOPT_XCONCAT(x, y) __GETOPT_CONCAT (x, y)
50 # define __GETOPT_ID(y) __GETOPT_XCONCAT (__GETOPT_PREFIX, y)
51 # define getopt __GETOPT_ID (getopt)
52 # define getopt_long __GETOPT_ID (getopt_long)
53 # define getopt_long_only __GETOPT_ID (getopt_long_only)
54 # define optarg __GETOPT_ID (optarg)
55 # define opterr __GETOPT_ID (opterr)
56 # define optind __GETOPT_ID (optind)
57 # define optopt __GETOPT_ID (optopt)
58 #endif
60 /* Standalone applications get correct prototypes for getopt_long and
61 getopt_long_only; they declare "char **argv". libc uses prototypes
62 with "char *const *argv" that are incorrect because getopt_long and
63 getopt_long_only can permute argv; this is required for backward
64 compatibility (e.g., for LSB 2.0.1).
66 This used to be `#if defined __GETOPT_PREFIX && !defined __need_getopt',
67 but it caused redefinition warnings if both unistd.h and getopt.h were
68 included, since unistd.h includes getopt.h having previously defined
69 __need_getopt.
71 The only place where __getopt_argv_const is used is in definitions
72 of getopt_long and getopt_long_only below, but these are visible
73 only if __need_getopt is not defined, so it is quite safe to rewrite
74 the conditional as follows:
76 #if !defined __need_getopt
77 # if defined __GETOPT_PREFIX
78 # define __getopt_argv_const /* empty */
79 # else
80 # define __getopt_argv_const const
81 # endif
82 #endif
84 /* If __GNU_LIBRARY__ is not already defined, either we are being used
85 standalone, or this is the first header included in the source file.
86 If we are being used with glibc, we need to include <features.h>, but
87 that does not exist if we are standalone. So: if __GNU_LIBRARY__ is
88 not defined, include <ctype.h>, which will pull in <features.h> for us
89 if it's from glibc. (Why ctype.h? It's guaranteed to exist and it
90 doesn't flood the namespace with stuff the way some other headers do.) */
91 #if !defined __GNU_LIBRARY__
92 # include <ctype.h>
93 #endif
95 #ifndef __THROW
96 # ifndef __GNUC_PREREQ
97 # define __GNUC_PREREQ(maj, min) (0)
98 # endif
99 # if defined __cplusplus && __GNUC_PREREQ (2,8)
100 # define __THROW throw ()
101 # else
102 # define __THROW
103 # endif
104 #endif
106 #ifdef __cplusplus
107 extern "C" {
108 #endif
110 /* For communication from `getopt' to the caller.
111 When `getopt' finds an option that takes an argument,
112 the argument value is returned here.
113 Also, when `ordering' is RETURN_IN_ORDER,
114 each non-option ARGV-element is returned here. */
116 extern char *optarg;
118 /* Index in ARGV of the next element to be scanned.
119 This is used for communication to and from the caller
120 and for communication between successive calls to `getopt'.
122 On entry to `getopt', zero means this is the first call; initialize.
124 When `getopt' returns -1, this is the index of the first of the
125 non-option elements that the caller should itself scan.
127 Otherwise, `optind' communicates from one call to the next
128 how much of ARGV has been scanned so far. */
130 extern int optind;
132 /* Callers store zero here to inhibit the error message `getopt' prints
133 for unrecognized options. */
135 extern int opterr;
137 /* Set to an option character which was unrecognized. */
139 extern int optopt;
141 #ifndef __need_getopt
142 /* Describe the long-named options requested by the application.
143 The LONG_OPTIONS argument to getopt_long or getopt_long_only is a vector
144 of `struct option' terminated by an element containing a name which is
145 zero.
147 The field `has_arg' is:
148 no_argument (or 0) if the option does not take an argument,
149 required_argument (or 1) if the option requires an argument,
150 optional_argument (or 2) if the option takes an optional argument.
152 If the field `flag' is not NULL, it points to a variable that is set
153 to the value given in the field `val' when the option is found, but
154 left unchanged if the option is not found.
156 To have a long-named option do something other than set an `int' to
157 a compiled-in constant, such as set a value from `optarg', set the
158 option's `flag' field to zero and its `val' field to a nonzero
159 value (the equivalent single-letter option character, if there is
160 one). For long options that have a zero `flag' field, `getopt'
161 returns the contents of the `val' field. */
163 struct option
165 const char *name;
166 /* has_arg can't be an enum because some compilers complain about
167 type mismatches in all the code that assumes it is an int. */
168 int has_arg;
169 int *flag;
170 int val;
173 /* Names for the values of the `has_arg' field of `struct option'. */
175 # define no_argument 0
176 # define required_argument 1
177 # define optional_argument 2
178 #endif /* need getopt */
181 /* Get definitions and prototypes for functions to process the
182 arguments in ARGV (ARGC of them, minus the program name) for
183 options given in OPTS.
185 Return the option character from OPTS just read. Return -1 when
186 there are no more options. For unrecognized options, or options
187 missing arguments, `optopt' is set to the option letter, and '?' is
188 returned.
190 The OPTS string is a list of characters which are recognized option
191 letters, optionally followed by colons, specifying that that letter
192 takes an argument, to be placed in `optarg'.
194 If a letter in OPTS is followed by two colons, its argument is
195 optional. This behavior is specific to the GNU `getopt'.
197 The argument `--' causes premature termination of argument
198 scanning, explicitly telling `getopt' that there are no more
199 options.
201 If OPTS begins with `--', then non-option arguments are treated as
202 arguments to the option '\0'. This behavior is specific to the GNU
203 `getopt'. */
205 extern int getopt (int ___argc, char *const *___argv, const char *__shortopts)
206 __THROW;
208 #ifndef __need_getopt
209 extern int getopt_long (int ___argc, char *__getopt_argv_const *___argv,
210 const char *__shortopts,
211 const struct option *__longopts, int *__longind)
212 __THROW;
213 extern int getopt_long_only (int ___argc, char *__getopt_argv_const *___argv,
214 const char *__shortopts,
215 const struct option *__longopts, int *__longind)
216 __THROW;
218 #endif
220 #ifdef __cplusplus
222 #endif
224 /* Make sure we later can get all the definitions and declarations. */
225 #undef __need_getopt
227 #endif /* getopt.h */
229 /* arch-tag: e36f5607-3ac6-4cdc-9aa7-c26c6525fe9b
230 (do not change this comment) */