xref: /freebsd/stand/libsa/getopt.c (revision d37eb51047221dc3322b34db1038ff3aa533883f)
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. Neither the name of the University nor the names of its contributors
14  *    may be used to endorse or promote products derived from this software
15  *    without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  */
29 
30 #include "stand.h"
31 #include <string.h>
32 
33 int	opterr = 1,		/* if error message should be printed */
34 	optind = 1,		/* index into parent argv vector */
35 	optopt,			/* character checked for validity */
36 	optreset;		/* reset getopt */
37 char	*optarg;		/* argument associated with option */
38 
39 #define	BADCH	(int)'?'
40 #define	BADARG	(int)':'
41 #define	EMSG	""
42 
43 /*
44  * getopt --
45  *	Parse argc/argv argument vector.
46  */
47 int
48 getopt(int nargc, char * const *nargv, const char *ostr)
49 {
50 	static char *place = EMSG;		/* option letter processing */
51 	char *oli;				/* option letter list index */
52 
53 	if (optreset || !*place) {		/* update scanning pointer */
54 		optreset = 0;
55 		if (optind >= nargc || *(place = nargv[optind]) != '-') {
56 			place = EMSG;
57 			return (-1);
58 		}
59 		if (place[1] && *++place == '-') {	/* found "--" */
60 			++optind;
61 			place = EMSG;
62 			return (-1);
63 		}
64 	}					/* option letter okay? */
65 	if ((optopt = (int)*place++) == (int)':' ||
66 	    !(oli = strchr(ostr, optopt))) {
67 		/*
68 		 * if the user didn't specify '-' as an option,
69 		 * assume it means -1.
70 		 */
71 		if (optopt == (int)'-')
72 			return (-1);
73 		if (!*place)
74 			++optind;
75 		if (opterr && *ostr != ':')
76 			(void)printf("illegal option -- %c\n", optopt);
77 		return (BADCH);
78 	}
79 	if (*++oli != ':') {			/* don't need argument */
80 		optarg = NULL;
81 		if (!*place)
82 			++optind;
83 	}
84 	else {					/* need an argument */
85 		if (*place)			/* no white space */
86 			optarg = place;
87 		else if (nargc <= ++optind) {	/* no arg */
88 			place = EMSG;
89 			if (*ostr == ':')
90 				return (BADARG);
91 			if (opterr)
92 				(void)printf("option requires an argument -- %c\n", optopt);
93 			return (BADCH);
94 		}
95 	 	else				/* white space */
96 			optarg = nargv[optind];
97 		place = EMSG;
98 		++optind;
99 	}
100 	return (optopt);			/* dump back option letter */
101 }
102