Add README
[xapian-trec.git] / getopt.h
blob0abce6e921dd83c812a4da6cc9af14fa717160c7
1 /* Declarations for getopt.
2 Copyright (C) 1989, 1990, 1991, 1992, 1993 Free Software Foundation, Inc.
4 This program is free software; you can redistribute it and/or modify it
5 under the terms of the GNU General Public License as published by the
6 Free Software Foundation; either version 2, or (at your option) any
7 later version.
9 This program is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 GNU General Public License for more details.
14 You should have received a copy of the GNU General Public License
15 along with this program; if not, write to the Free Software
16 Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */
18 #ifndef _GETOPT_H
19 #define _GETOPT_H 1
21 #ifdef __cplusplus
22 extern "C" {
23 #endif
25 /* For communication from `getopt' to the caller.
26 When `getopt' finds an option that takes an argument,
27 the argument value is returned here.
28 Also, when `ordering' is RETURN_IN_ORDER,
29 each non-option ARGV-element is returned here. */
31 extern char *optarg;
33 /* Index in ARGV of the next element to be scanned.
34 This is used for communication to and from the caller
35 and for communication between successive calls to `getopt'.
37 On entry to `getopt', zero means this is the first call; initialize.
39 When `getopt' returns EOF, this is the index of the first of the
40 non-option elements that the caller should itself scan.
42 Otherwise, `optind' communicates from one call to the next
43 how much of ARGV has been scanned so far. */
45 extern int optind;
47 /* Callers store zero here to inhibit the error message `getopt' prints
48 for unrecognized options. */
50 extern int opterr;
52 /* Set to an option character which was unrecognized. */
54 extern int optopt;
56 /* Describe the long-named options requested by the application.
57 The LONG_OPTIONS argument to getopt_long or getopt_long_only is a vector
58 of `struct option' terminated by an element containing a name which is
59 zero.
61 The field `has_arg' is:
62 no_argument (or 0) if the option does not take an argument,
63 required_argument (or 1) if the option requires an argument,
64 optional_argument (or 2) if the option takes an optional argument.
66 If the field `flag' is not NULL, it points to a variable that is set
67 to the value given in the field `val' when the option is found, but
68 left unchanged if the option is not found.
70 To have a long-named option do something other than set an `int' to
71 a compiled-in constant, such as set a value from `optarg', set the
72 option's `flag' field to zero and its `val' field to a nonzero
73 value (the equivalent single-letter option character, if there is
74 one). For long options that have a zero `flag' field, `getopt'
75 returns the contents of the `val' field. */
77 struct option
79 #if __STDC__
80 const char *name;
81 #else
82 char *name;
83 #endif
84 /* has_arg can't be an enum because some compilers complain about
85 type mismatches in all the code that assumes it is an int. */
86 int has_arg;
87 int *flag;
88 int val;
91 /* Names for the values of the `has_arg' field of `struct option'. */
93 #define no_argument 0
94 #define required_argument 1
95 #define optional_argument 2
97 #if __STDC__ || defined(PROTO)
98 #if defined(__GNU_LIBRARY__)
99 /* Many other libraries have conflicting prototypes for getopt, with
100 differences in the consts, in stdlib.h. To avoid compilation
101 errors, only prototype getopt for the GNU C library. */
102 extern int getopt (int argc, char *const *argv, const char *shortopts);
103 #endif /* not __GNU_LIBRARY__ */
104 extern int getopt_long (int argc, char *const *argv, const char *shortopts,
105 const struct option *longopts, int *longind);
106 extern int getopt_long_only (int argc, char *const *argv,
107 const char *shortopts,
108 const struct option *longopts, int *longind);
110 /* Internal only. Users should not call this directly. */
111 extern int _getopt_internal (int argc, char *const *argv,
112 const char *shortopts,
113 const struct option *longopts, int *longind,
114 int long_only);
115 #else /* not __STDC__ */
116 extern int getopt ();
117 extern int getopt_long ();
118 extern int getopt_long_only ();
120 extern int _getopt_internal ();
121 #endif /* not __STDC__ */
123 #ifdef __cplusplus
125 #endif
127 #endif /* _GETOPT_H */