xref: /dragonfly/lib/libc/stdlib/getopt.c (revision 7b0266d8)
1 /*	$NetBSD: getopt.c,v 1.26 2003/08/07 16:43:40 agc Exp $	*/
2 
3 /*
4  * Copyright (c) 1987, 1993, 1994
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. All advertising materials mentioning features or use of this software
16  *    must display the following acknowledgement:
17  *	This product includes software developed by the University of
18  *	California, Berkeley and its contributors.
19  * 4. Neither the name of the University nor the names of its contributors
20  *    may be used to endorse or promote products derived from this software
21  *    without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  *
35  * @(#)getopt.c	8.3 (Berkeley) 4/27/95
36  * $FreeBSD: src/lib/libc/stdlib/getopt.c,v 1.2.2.2 2001/08/26 03:36:04 jkoshy Exp $
37  * $DragonFly: src/lib/libc/stdlib/getopt.c,v 1.3 2004/07/15 04:10:33 hmp Exp $
38  */
39 
40 #include <stdio.h>
41 #include <stdlib.h>
42 #include <string.h>
43 
44 int	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 */
48 char	*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  */
58 int
59 getopt(nargc, nargv, ostr)
60 	int nargc;
61 	char * const nargv[];
62 	const char *ostr;
63 {
64 	static char *place = EMSG;		/* option letter processing */
65 	char *oli;				/* option letter list index */
66 
67 	if (optreset || *place == 0) {		/* update scanning pointer */
68 		optreset = 0;
69 		place = nargv[optind];
70 		if (optind >= nargc || *place++ != '-') {
71 			/* Argument is absent or is not an option */
72 			place = EMSG;
73 			return (-1);
74 		}
75 		optopt = *place++;
76 		if (optopt == '-' && *place == 0) {
77 			/* "--" => end of options */
78 			++optind;
79 			place = EMSG;
80 			return (-1);
81 		}
82 		if (optopt == 0) {
83 			/* Solitary '-', treat as a '-' option
84 			   if the program (eg su) is looking for it. */
85 			place = EMSG;
86 			if (strchr(ostr, '-') == NULL)
87 				return (-1);
88 			optopt = '-';
89 		}
90 	} else
91 		optopt = *place++;
92 
93 	/* See if option letter is one the caller wanted... */
94 	if (optopt == ':' || (oli = strchr(ostr, optopt)) == NULL) {
95 		if (*place == 0)
96 			++optind;
97 		if (opterr && *ostr != ':')
98 			(void)fprintf(stderr,
99 			    "%s: illegal option -- %c\n", getprogname(),
100 			    optopt);
101 		return (BADCH);
102 	}
103 
104 	/* Does this option need an argument? */
105 	if (oli[1] != ':') {
106 		/* don't need argument */
107 		optarg = NULL;
108 		if (*place == 0)
109 			++optind;
110 	} else {
111 		/* Option-argument is either the rest of this argument or the
112 		   entire next argument. */
113 		if (*place)
114 			optarg = place;
115 		else if (nargc > ++optind)
116 			optarg = nargv[optind];
117 		else {
118 			/* option-argument absent */
119 			place = EMSG;
120 			if (*ostr == ':')
121 				return (BADARG);
122 			if (opterr)
123 				(void)fprintf(stderr,
124 				    "%s: option requires an argument -- %c\n",
125 				    getprogname(), optopt);
126 			return (BADCH);
127 		}
128 		place = EMSG;
129 		++optind;
130 	}
131 	return (optopt);			/* return option letter */
132 }
133