xref: /freebsd/lib/libc/stdlib/getopt.c (revision 1e413cf93298b5b97441a21d9a50fdcd0ee9945e)
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  * 4. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 #if defined(LIBC_SCCS) && !defined(lint)
33 static char sccsid[] = "@(#)getopt.c	8.3 (Berkeley) 4/27/95";
34 #endif /* LIBC_SCCS and not lint */
35 #include <sys/cdefs.h>
36 __FBSDID("$FreeBSD$");
37 
38 #include "namespace.h"
39 #include <stdio.h>
40 #include <stdlib.h>
41 #include <string.h>
42 #include <unistd.h>
43 #include "un-namespace.h"
44 
45 #include "libc_private.h"
46 
47 int	opterr = 1,		/* if error message should be printed */
48 	optind = 1,		/* index into parent argv vector */
49 	optopt,			/* character checked for validity */
50 	optreset;		/* reset getopt */
51 char	*optarg;		/* argument associated with option */
52 
53 #define	BADCH	(int)'?'
54 #define	BADARG	(int)':'
55 #define	EMSG	""
56 
57 /*
58  * getopt --
59  *	Parse argc/argv argument vector.
60  */
61 int
62 getopt(nargc, nargv, ostr)
63 	int nargc;
64 	char * const nargv[];
65 	const char *ostr;
66 {
67 	static char *place = EMSG;		/* option letter processing */
68 	char *oli;				/* option letter list index */
69 
70 	if (optreset || *place == 0) {		/* update scanning pointer */
71 		optreset = 0;
72 		place = nargv[optind];
73 		if (optind >= nargc || *place++ != '-') {
74 			/* Argument is absent or is not an option */
75 			place = EMSG;
76 			return (-1);
77 		}
78 		optopt = *place++;
79 		if (optopt == '-' && *place == 0) {
80 			/* "--" => end of options */
81 			++optind;
82 			place = EMSG;
83 			return (-1);
84 		}
85 		if (optopt == 0) {
86 			/* Solitary '-', treat as a '-' option
87 			   if the program (eg su) is looking for it. */
88 			place = EMSG;
89 			if (strchr(ostr, '-') == NULL)
90 				return (-1);
91 			optopt = '-';
92 		}
93 	} else
94 		optopt = *place++;
95 
96 	/* See if option letter is one the caller wanted... */
97 	if (optopt == ':' || (oli = strchr(ostr, optopt)) == NULL) {
98 		if (*place == 0)
99 			++optind;
100 		if (opterr && *ostr != ':')
101 			(void)fprintf(stderr,
102 			    "%s: illegal option -- %c\n", _getprogname(),
103 			    optopt);
104 		return (BADCH);
105 	}
106 
107 	/* Does this option need an argument? */
108 	if (oli[1] != ':') {
109 		/* don't need argument */
110 		optarg = NULL;
111 		if (*place == 0)
112 			++optind;
113 	} else {
114 		/* Option-argument is either the rest of this argument or the
115 		   entire next argument. */
116 		if (*place)
117 			optarg = place;
118 		else if (nargc > ++optind)
119 			optarg = nargv[optind];
120 		else {
121 			/* option-argument absent */
122 			place = EMSG;
123 			if (*ostr == ':')
124 				return (BADARG);
125 			if (opterr)
126 				(void)fprintf(stderr,
127 				    "%s: option requires an argument -- %c\n",
128 				    _getprogname(), optopt);
129 			return (BADCH);
130 		}
131 		place = EMSG;
132 		++optind;
133 	}
134 	return (optopt);			/* return option letter */
135 }
136