getopt.c revision 38452 
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
38#include "stand.h"
39#include <string.h>
40
41int	opterr = 1,		/* if error message should be printed */
42	optind = 1,		/* index into parent argv vector */
43	optopt,			/* character checked for validity */
44	optreset;		/* reset getopt */
45char	*optarg;		/* argument associated with option */
46
47#define	BADCH	(int)'?'
48#define	BADARG	(int)':'
49#define	EMSG	""
50
51/*
52 * getopt --
53 *	Parse argc/argv argument vector.
54 */
55int
56getopt(nargc, nargv, ostr)
57	int nargc;
58	char * const *nargv;
59	const char *ostr;
60{
61	static char *place = EMSG;		/* option letter processing */
62	char *oli;				/* option letter list index */
63
64	if (optreset || !*place) {		/* update scanning pointer */
65		optreset = 0;
66		if (optind >= nargc || *(place = nargv[optind]) != '-') {
67			place = EMSG;
68			return (-1);
69		}
70		if (place[1] && *++place == '-') {	/* found "--" */
71			++optind;
72			place = EMSG;
73			return (-1);
74		}
75	}					/* option letter okay? */
76	if ((optopt = (int)*place++) == (int)':' ||
77	    !(oli = strchr(ostr, optopt))) {
78		/*
79		 * if the user didn't specify '-' as an option,
80		 * assume it means -1.
81		 */
82		if (optopt == (int)'-')
83			return (-1);
84		if (!*place)
85			++optind;
86		if (opterr && *ostr != ':')
87			(void)printf("illegal option -- %c\n", optopt);
88		return (BADCH);
89	}
90	if (*++oli != ':') {			/* don't need argument */
91		optarg = NULL;
92		if (!*place)
93			++optind;
94	}
95	else {					/* need an argument */
96		if (*place)			/* no white space */
97			optarg = place;
98		else if (nargc <= ++optind) {	/* no arg */
99			place = EMSG;
100			if (*ostr == ':')
101				return (BADARG);
102			if (opterr)
103				(void)printf("option requires an argument -- %c\n", optopt);
104			return (BADCH);
105		}
106	 	else				/* white space */
107			optarg = nargv[optind];
108		place = EMSG;
109		++optind;
110	}
111	return (optopt);			/* dump back option letter */
112}
113