getopt.c

操作系统SunOS 4.1.3版本的源码

#if !defined(lint) && defined(SCCSIDS)
static	char sccsid[] = "@(#)getopt.c 1.1 92/07/30 SMI";
/* from 4.3BSD-tahoe 4.9 6/23/89 */
#endif

/*
 * Copyright (c) 1989 Sun Microsystems, Inc.
 */
/*
 * Copyright (c) 1987 Regents of the University of California.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms are permitted
 * provided that the above copyright notice and this paragraph are
 * duplicated in all such forms and that any documentation,
 * advertising materials, and other materials related to such
 * distribution and use acknowledge that the software was developed
 * by the University of California, Berkeley.  The name of the
 * University may not be used to endorse or promote products derived
 * from this software without specific prior written permission.
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 */

/* LINTLIBRARY */

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

/*
 * get option letter from argument vector
 */
/* See lib/libc/gen/common/optind.c for next 3 definitions. */
extern char	*optarg;	/* argument associated with option */
extern int	opterr;		/* if error message should be printed */
extern int	optind;		/* index into parent argv vector */
int		optopt;		/* character checked for validity */


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

getopt(nargc, nargv, ostr)
	int nargc;
	char **nargv, *ostr;
{
	static char *place = EMSG;		/* option letter processing */
	register char *oli;			/* option letter list index */
	char *p;

	if (!*place) {				/* update scanning pointer */
		if (optind >= nargc || *(place = nargv[optind]) != '-') {
			place = EMSG;
			return (EOF);
		}
		if (place[1] && *++place == '-') {	/* found "--" */
			++optind;
			place = EMSG;
			return (EOF);
		}
	}					/* option letter okay? */
	if ((optopt = (int)*place++) == (int)':' ||
	    !(oli = strchr(ostr, optopt))) {

		/*
		 * For backwards compatibility: don't treat '-' as an
		 * option letter unless caller explicitly asked for it.
		 */
		if (optopt == (int)'-')
			return (EOF);
		if (!*place)
			++optind;
		if (opterr) {
			if (!(p = strrchr(*nargv, '/')))
				p = *nargv;
			else
				++p;
			(void)fprintf(stderr, "%s: illegal option -- %c\n",
			    p, 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 (!(p = strrchr(*nargv, '/')))
				p = *nargv;
			else
				++p;
			if (opterr)
				(void)fprintf(stderr,
				    "%s: option requires an argument -- %c\n",
				    p, optopt);
			return (BADCH);
		} else				/* white space */
			optarg = nargv[optind];
		place = EMSG;
		++optind;
	}
	return (optopt);			/* dump back option letter */
}