codec/getopt.c

/*
 * Copyright (c) 1987, 1993, 1994
 *	The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

/* last review : october 29th, 2002 */

#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)getopt.c	8.3 (Berkeley) 4/27/95";
#endif				/* LIBC_SCCS and not lint */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

int opterr = 1,			/* if error message should be printed */
 optind = 1,			/* index into parent argv vector */
 optopt,				/* character checked for validity */
 optreset;				/* reset getopt */
char *optarg;			/* argument associated with option */

#define	BADCH	(int)'?'
#define	BADARG	(int)':'
#define	EMSG	""

/*
 * getopt --
 *	Parse argc/argv argument vector.
 */
int getopt(int nargc, char *const *nargv, const char *ostr) {
	
  #  define __progname nargv[0] /* program name */
	
  static char *place = EMSG;	/* option letter processing */
  char *oli;					/* option letter list index */

  if (optreset || !*place) {	/* update scanning pointer */
    optreset = 0;
    if (optind >= nargc || *(place = nargv[optind]) != '-') {
      place = EMSG;
      return (-1);
    }
    if (place[1] && *++place == '-') {	/* found "--" */
      ++optind;
      place = EMSG;
      return (-1);
    }
  }	/* option letter okay? */
  
  if ((optopt = (int) *place++) == (int) ':' || !(oli = strchr(ostr, optopt))) {
    /* if the user didn't specify '-' as an option, assume it means -1. */
    if (optopt == (int) '-')
      return (-1);
    if (!*place)
      ++optind;
    if (opterr && *ostr != ':')
      (void) fprintf(stdout,"[ERROR] %s: illegal option -- %c\n", __progname, optopt);
    return (BADCH);
  }

  if (*++oli != ':') {		/* don't need argument */
    optarg = NULL;
    if (!*place)
      ++optind;
  } else {					/* need an argument */
    if (*place)						/* no white space */
      optarg = place;
    else if (nargc <= ++optind) {	/* no arg */
      place = EMSG;
      if (*ostr == ':')
		return (BADARG);
      if (opterr)
		(void) fprintf(stdout, "[ERROR] %s: option requires an argument -- %c\n", __progname, optopt);
      return (BADCH);
    } else							/* white space */
      optarg = nargv[optind];
    place = EMSG;
    ++optind;
  }
  return (optopt);		/* dump back option letter */
}