xref: /freebsd/lib/libc/stdlib/getopt.c (revision 6b3455a7665208c366849f0b2b3bc916fb97516e)
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 
36 #if defined(LIBC_SCCS) && !defined(lint)
37 static char sccsid[] = "@(#)getopt.c	8.3 (Berkeley) 4/27/95";
38 #endif /* LIBC_SCCS and not lint */
39 #include <sys/cdefs.h>
40 __FBSDID("$FreeBSD$");
41 
42 #include "namespace.h"
43 #include <stdio.h>
44 #include <stdlib.h>
45 #include <string.h>
46 #include <unistd.h>
47 #include "un-namespace.h"
48 
49 #include "libc_private.h"
50 
51 int	opterr = 1,		/* if error message should be printed */
52 	optind = 1,		/* index into parent argv vector */
53 	optopt,			/* character checked for validity */
54 	optreset;		/* reset getopt */
55 char	*optarg;		/* argument associated with option */
56 
57 #define	BADCH	(int)'?'
58 #define	BADARG	(int)':'
59 #define	EMSG	""
60 
61 /*
62  * getopt --
63  *	Parse argc/argv argument vector.
64  */
65 int
66 getopt(nargc, nargv, ostr)
67 	int nargc;
68 	char * const nargv[];
69 	const char *ostr;
70 {
71 	static char *place = EMSG;		/* option letter processing */
72 	char *oli;				/* option letter list index */
73 
74 	if (optreset || *place == 0) {		/* update scanning pointer */
75 		optreset = 0;
76 		place = nargv[optind];
77 		if (optind >= nargc || *place++ != '-') {
78 			/* Argument is absent or is not an option */
79 			place = EMSG;
80 			return (-1);
81 		}
82 		optopt = *place++;
83 		if (optopt == '-' && *place == 0) {
84 			/* "--" => end of options */
85 			++optind;
86 			place = EMSG;
87 			return (-1);
88 		}
89 		if (optopt == 0) {
90 			/* Solitary '-', treat as a '-' option
91 			   if the program (eg su) is looking for it. */
92 			place = EMSG;
93 			if (strchr(ostr, '-') == NULL)
94 				return (-1);
95 			optopt = '-';
96 		}
97 	} else
98 		optopt = *place++;
99 
100 	/* See if option letter is one the caller wanted... */
101 	if (optopt == ':' || (oli = strchr(ostr, optopt)) == NULL) {
102 		if (*place == 0)
103 			++optind;
104 		if (opterr && *ostr != ':')
105 			(void)fprintf(stderr,
106 			    "%s: illegal option -- %c\n", _getprogname(),
107 			    optopt);
108 		return (BADCH);
109 	}
110 
111 	/* Does this option need an argument? */
112 	if (oli[1] != ':') {
113 		/* don't need argument */
114 		optarg = NULL;
115 		if (*place == 0)
116 			++optind;
117 	} else {
118 		/* Option-argument is either the rest of this argument or the
119 		   entire next argument. */
120 		if (*place)
121 			optarg = place;
122 		else if (nargc > ++optind)
123 			optarg = nargv[optind];
124 		else {
125 			/* option-argument absent */
126 			place = EMSG;
127 			if (*ostr == ':')
128 				return (BADARG);
129 			if (opterr)
130 				(void)fprintf(stderr,
131 				    "%s: option requires an argument -- %c\n",
132 				    _getprogname(), optopt);
133 			return (BADCH);
134 		}
135 		place = EMSG;
136 		++optind;
137 	}
138 	return (optopt);			/* return option letter */
139 }
140