lib/getopt.h

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /* Declarations for getopt.
   3  * Copyright (C) 1989,90,91,92,93,94,96,97 Free Software Foundation, Inc.
   4  *
   5  * NOTE: The canonical source of this file is maintained with the GNU C Library.
   6  * Bugs can be reported to bug-glibc@gnu.org.
   7  */
   8
   9 #ifndef _GETOPT_H
  10 #define _GETOPT_H 1
  11
  12 /*
  13  * The operating system may or may not provide getopt_long(), and if
  14  * so it may or may not be a version we are willing to use.  Our
  15  * strategy is to declare getopt here, and then provide code unless
  16  * the supplied version is adequate.  The difficult case is when a
  17  * declaration for getopt is provided, as our declaration must match.
  18  *
  19  * XXX Arguably this version should be named differently, and the
  20  * local names defined to refer to the system version when we choose
  21  * to use the system version.
  22  */
  23
  24 #ifdef __cplusplus
  25 extern "C" {
  26 #endif
  27
  28 /* For communication from `getopt' to the caller.
  29    When `getopt' finds an option that takes an argument,
  30    the argument value is returned here.
  31    Also, when `ordering' is RETURN_IN_ORDER,
  32    each non-option ARGV-element is returned here.  */
  33
  34 extern char *optarg;
  35
  36 /* Index in ARGV of the next element to be scanned.
  37    This is used for communication to and from the caller
  38    and for communication between successive calls to `getopt'.
  39
  40    On entry to `getopt', zero means this is the first call; initialize.
  41
  42    When `getopt' returns -1, this is the index of the first of the
  43    non-option elements that the caller should itself scan.
  44
  45    Otherwise, `optind' communicates from one call to the next
  46    how much of ARGV has been scanned so far.  */
  47
  48 extern int optind;
  49
  50 /* Callers store zero here to inhibit the error message `getopt' prints
  51    for unrecognized options.  */
  52
  53 extern int opterr;
  54
  55 /* Set to an option character which was unrecognized.  */
  56
  57 extern int optopt;
  58
  59 /* Describe the long-named options requested by the application.
  60    The LONG_OPTIONS argument to getopt_long or getopt_long_only is a vector
  61    of `struct option' terminated by an element containing a name which is
  62    zero.
  63
  64    The field `has_arg' is:
  65    no_argument          (or 0) if the option does not take an argument,
  66    required_argument    (or 1) if the option requires an argument,
  67    optional_argument    (or 2) if the option takes an optional argument.
  68
  69    If the field `flag' is not NULL, it points to a variable that is set
  70    to the value given in the field `val' when the option is found, but
  71    left unchanged if the option is not found.
  72
  73    To have a long-named option do something other than set an `int' to
  74    a compiled-in constant, such as set a value from `optarg', set the
  75    option's `flag' field to zero and its `val' field to a nonzero
  76    value (the equivalent single-letter option character, if there is
  77    one).  For long options that have a zero `flag' field, `getopt'
  78    returns the contents of the `val' field.  */
  79
  80 struct option {
  81 #if defined(__STDC__) && __STDC__
  82         const char *name;
  83 #else
  84         char *name;
  85 #endif
  86         /* has_arg can't be an enum because some compilers complain about
  87            type mismatches in all the code that assumes it is an int.  */
  88         int has_arg;
  89         int *flag;
  90         int val;
  91 };
  92
  93 /* Names for the values of the `has_arg' field of `struct option'.  */
  94
  95 #define no_argument             0
  96 #define required_argument       1
  97 #define optional_argument       2
  98
  99 #if defined(__STDC__) && __STDC__
 100
 101 #ifdef REALLY_NEED_PLAIN_GETOPT
 102
 103 /*
 104  * getopt is defined in POSIX.2.  Assume that if the system defines
 105  * getopt that it complies with POSIX.2.  If not, an autoconf test
 106  * should be written to define NONPOSIX_GETOPT_DEFINITION.
 107  */
 108 #ifndef NONPOSIX_GETOPT_DEFINITION
 109 extern int getopt(int argc, char *const *argv, const char *shortopts);
 110 #else  /* NONPOSIX_GETOPT_DEFINITION */
 111 extern int getopt(void);
 112 #endif /* NONPOSIX_GETOPT_DEFINITION */
 113
 114 #endif
 115
 116
 117 extern int getopt_long(int argc, char *const *argv, const char *shortopts,
 118                        const struct option *longopts, int *longind);
 119 extern int getopt_long_only(int argc, char *const *argv, const char *shortopts,
 120                             const struct option *longopts, int *longind);
 121
 122 /* Internal only.  Users should not call this directly.  */
 123 extern int _getopt_internal(int argc, char *const *argv, const char *shortopts,
 124                             const struct option *longopts, int *longind,
 125                             int long_only);
 126 #else /* not __STDC__ */
 127
 128 #ifdef REALLY_NEED_PLAIN_GETOPT
 129 extern int getopt();
 130 #endif /* REALLY_NEED_PLAIN_GETOPT */
 131
 132 extern int getopt_long();
 133 extern int getopt_long_only();
 134
 135 extern int _getopt_internal();
 136
 137 #endif /* __STDC__ */
 138
 139 #ifdef __cplusplus
 140 }
 141 #endif
 142
 143 #endif /* getopt.h */