xref: /freebsd/stand/libsa/getopt.c (revision 6137b5f7b8c183ee8806d79b3f1d8e5e3ddb3df3)
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 <sys/cdefs.h>
31 
32 #include "stand.h"
33 #include <string.h>
34 
35 int	opterr = 1,		/* if error message should be printed */
36 	optind = 1,		/* index into parent argv vector */
37 	optopt,			/* character checked for validity */
38 	optreset;		/* reset getopt */
39 char	*optarg;		/* argument associated with option */
40 
41 #define	BADCH	(int)'?'
42 #define	BADARG	(int)':'
43 #define	EMSG	""
44 
45 /*
46  * getopt --
47  *	Parse argc/argv argument vector.
48  */
49 int
50 getopt(int nargc, char * const *nargv, const char *ostr)
51 {
52 	static char *place = EMSG;		/* option letter processing */
53 	char *oli;				/* option letter list index */
54 
55 	if (optreset || !*place) {		/* update scanning pointer */
56 		optreset = 0;
57 		if (optind >= nargc || *(place = nargv[optind]) != '-') {
58 			place = EMSG;
59 			return (-1);
60 		}
61 		if (place[1] && *++place == '-') {	/* found "--" */
62 			++optind;
63 			place = EMSG;
64 			return (-1);
65 		}
66 	}					/* option letter okay? */
67 	if ((optopt = (int)*place++) == (int)':' ||
68 	    !(oli = strchr(ostr, optopt))) {
69 		/*
70 		 * if the user didn't specify '-' as an option,
71 		 * assume it means -1.
72 		 */
73 		if (optopt == (int)'-')
74 			return (-1);
75 		if (!*place)
76 			++optind;
77 		if (opterr && *ostr != ':')
78 			(void)printf("illegal option -- %c\n", optopt);
79 		return (BADCH);
80 	}
81 	if (*++oli != ':') {			/* don't need argument */
82 		optarg = NULL;
83 		if (!*place)
84 			++optind;
85 	}
86 	else {					/* need an argument */
87 		if (*place)			/* no white space */
88 			optarg = place;
89 		else if (nargc <= ++optind) {	/* no arg */
90 			place = EMSG;
91 			if (*ostr == ':')
92 				return (BADARG);
93 			if (opterr)
94 				(void)printf("option requires an argument -- %c\n", optopt);
95 			return (BADCH);
96 		}
97 	 	else				/* white space */
98 			optarg = nargv[optind];
99 		place = EMSG;
100 		++optind;
101 	}
102 	return (optopt);			/* dump back option letter */
103 }
104