getopt.h

LZSS 压缩/解压算法 算法简单

/* Declarations for getopt.
Copyright (C) 1989, 90, 91, 92, 93, 94 Free Software Foundation, Inc.

This file is part of the GNU C Library.  Its master source is NOT part of
the C library, however.  The master source lives in /gd/gnu/lib.

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

The GNU C Library 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
Library General Public License for more details.

You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB.  If
not, write to the Free Software Foundation, Inc., 675 Mass Ave,
Cambridge, MA 02139, USA.  */

#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 defined (__STDC__) && __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 defined (__STDC__) && __STDC__
#ifdef __GNU_LIBRARY__
/* Many other libraries have conflicting prototypes for getopt, with
differences in the consts, in stdlib.h.  To avoid compilation
errors, only prototype getopt for the GNU C library.  */
extern int getopt (int argc, char *const *argv, const char *shortopts);
#else /* not __GNU_LIBRARY__ */
extern int getopt ();
#endif /* __GNU_LIBRARY__ */
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 /* __STDC__ */

#ifdef	__cplusplus
}
#endif

#endif /* _GETOPT_H */