xref: /openbsd/gnu/usr.bin/cvs/lib/getopt.h (revision 892c0aad)

/* Declarations for getopt.
   Copyright (C) 1989, 1990, 1991, 1992, 1993 Free Software Foundation, Inc.

   This program is free software; you can redistribute it and/or modify it
   under the terms of the GNU General Public License as published by the
   Free Software Foundation; either version 2, or (at your option) any
   later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.  */

#ifndef _GETOPT_H
#define _GETOPT_H 1

#ifdef	__cplusplus
extern "C" {
#endif

/* For communication from `getopt' to the caller.
   When `getopt' finds an option that takes an argument,
   the argument value is returned here.
   Also, when `ordering' is RETURN_IN_ORDER,
   each non-option ARGV-element is returned here.  */

extern char *optarg;

/* Index in ARGV of the next element to be scanned.
   This is used for communication to and from the caller
   and for communication between successive calls to `getopt'.

   On entry to `getopt', zero means this is the first call; initialize.

   When `getopt' returns EOF, this is the index of the first of the
   non-option elements that the caller should itself scan.

   Otherwise, `optind' communicates from one call to the next
   how much of ARGV has been scanned so far.  */

extern int optind;

/* Callers store zero here to inhibit the error message `getopt' prints
   for unrecognized options.  */

extern int opterr;

/* Set to an option character which was unrecognized.  */

extern int optopt;

/* Describe the long-named options requested by the application.
   The LONG_OPTIONS argument to getopt_long or getopt_long_only is a vector
   of `struct option' terminated by an element containing a name which is
   zero.

   The field `has_arg' is:
   no_argument		(or 0) if the option does not take an argument,
   required_argument	(or 1) if the option requires an argument,
   optional_argument 	(or 2) if the option takes an optional argument.

   If the field `flag' is not NULL, it points to a variable that is set
   to the value given in the field `val' when the option is found, but
   left unchanged if the option is not found.

   To have a long-named option do something other than set an `int' to
   a compiled-in constant, such as set a value from `optarg', set the
   option's `flag' field to zero and its `val' field to a nonzero
   value (the equivalent single-letter option character, if there is
   one).  For long options that have a zero `flag' field, `getopt'
   returns the contents of the `val' field.  */

struct option
{
#if	__STDC__
  const char *name;
#else
  char *name;
#endif
  /* has_arg can't be an enum because some compilers complain about
     type mismatches in all the code that assumes it is an int.  */
  int has_arg;
  int *flag;
  int val;
};

/* Names for the values of the `has_arg' field of `struct option'.  */

#define	no_argument		0
#define required_argument	1
#define optional_argument	2

#if __STDC__
/* Many other libraries have conflicting prototypes for getopt, with
   differences in the consts, in stdlib.h.  We used to try to prototype
   it if __GNU_LIBRARY__ but that wasn't problem free either (I'm not sure
   exactly why), and there is no particular need to prototype it.
   We really shouldn't be trampling on the system's namespace at all by
   declaring getopt() but that is a bigger issue.  */
extern int getopt ();

extern int getopt_long (int argc, char *const *argv, const char *shortopts,
		        const struct option *longopts, int *longind);
extern int getopt_long_only (int argc, char *const *argv,
			     const char *shortopts,
		             const struct option *longopts, int *longind);

/* Internal only.  Users should not call this directly.  */
extern int _getopt_internal (int argc, char *const *argv,
			     const char *shortopts,
		             const struct option *longopts, int *longind,
			     int long_only);
#else /* not __STDC__ */
extern int getopt ();
extern int getopt_long ();
extern int getopt_long_only ();

extern int _getopt_internal ();
#endif /* not __STDC__ */

#ifdef	__cplusplus
}
#endif

#endif /* _GETOPT_H */