getopt.c revision 92986 
1/*
2 * Copyright (c) 1987, 1993, 1994
3 *	The Regents of the University of California.  All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 * 3. All advertising materials mentioning features or use of this software
14 *    must display the following acknowledgement:
15 *	This product includes software developed by the University of
16 *	California, Berkeley and its contributors.
17 * 4. Neither the name of the University nor the names of its contributors
18 *    may be used to endorse or promote products derived from this software
19 *    without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 */
33
34#if defined(LIBC_SCCS) && !defined(lint)
35static char sccsid[] = "@(#)getopt.c	8.3 (Berkeley) 4/27/95";
36#endif /* LIBC_SCCS and not lint */
37#include <sys/cdefs.h>
38__FBSDID("$FreeBSD: head/lib/libc/stdlib/getopt.c 92986 2002-03-22 21:53:29Z obrien $");
39
40#include <stdio.h>
41#include <stdlib.h>
42#include <string.h>
43
44int	opterr = 1,		/* if error message should be printed */
45	optind = 1,		/* index into parent argv vector */
46	optopt,			/* character checked for validity */
47	optreset;		/* reset getopt */
48char	*optarg;		/* argument associated with option */
49
50#define	BADCH	(int)'?'
51#define	BADARG	(int)':'
52#define	EMSG	""
53
54/*
55 * getopt --
56 *	Parse argc/argv argument vector.
57 */
58int
59getopt(nargc, nargv, ostr)
60	int nargc;
61	char * const *nargv;
62	const char *ostr;
63{
64	extern char *__progname;
65	static char *place = EMSG;		/* option letter processing */
66	char *oli;				/* option letter list index */
67
68	if (optreset || !*place) {		/* update scanning pointer */
69		optreset = 0;
70		if (optind >= nargc || *(place = nargv[optind]) != '-') {
71			place = EMSG;
72			return (-1);
73		}
74		if (place[1] && *++place == '-') {	/* found "--" */
75			++optind;
76			place = EMSG;
77			return (-1);
78		}
79	}					/* option letter okay? */
80	if ((optopt = (int)*place++) == (int)':' ||
81	    !(oli = strchr(ostr, optopt))) {
82		/*
83		 * if the user didn't specify '-' as an option,
84		 * assume it means -1.
85		 */
86		if (optopt == (int)'-')
87			return (-1);
88		if (!*place)
89			++optind;
90		if (opterr && *ostr != ':' && optopt != BADCH)
91			(void)fprintf(stderr,
92			    "%s: illegal option -- %c\n", __progname, optopt);
93		return (BADCH);
94	}
95	if (*++oli != ':') {			/* don't need argument */
96		optarg = NULL;
97		if (!*place)
98			++optind;
99	}
100	else {					/* need an argument */
101		if (*place)			/* no white space */
102			optarg = place;
103		else if (nargc <= ++optind) {	/* no arg */
104			place = EMSG;
105			if (*ostr == ':')
106				return (BADARG);
107			if (opterr)
108				(void)fprintf(stderr,
109				    "%s: option requires an argument -- %c\n",
110				    __progname, optopt);
111			return (BADCH);
112		}
113	 	else				/* white space */
114			optarg = nargv[optind];
115		place = EMSG;
116		++optind;
117	}
118	return (optopt);			/* dump back option letter */
119}
120