xref: /freebsd/lib/libc/stdlib/getopt.c (revision fcb560670601b2a4d87bb31d7531c8dcc37ee71b)
1 /*	$NetBSD: getopt.c,v 1.29 2014/06/05 22:00:22 christos 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. 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(int nargc, char * const nargv[], 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 (oli[2] == ':')
116 			/*
117 			 * GNU Extension, for optional arguments if the rest of
118 			 * the argument is empty, we return NULL
119 			 */
120 			optarg = NULL;
121 		else if (nargc > ++optind)
122 			optarg = nargv[optind];
123 		else {
124 			/* option-argument absent */
125 			place = EMSG;
126 			if (*ostr == ':')
127 				return (BADARG);
128 			if (opterr)
129 				(void)fprintf(stderr,
130 				    "%s: option requires an argument -- %c\n",
131 				    _getprogname(), optopt);
132 			return (BADCH);
133 		}
134 		place = EMSG;
135 		++optind;
136 	}
137 	return (optopt);			/* return option letter */
138 }
139