xref: /dragonfly/lib/libc/stdlib/getopt.c (revision 9ef1e017)
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. 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  * @(#)getopt.c	8.3 (Berkeley) 4/27/95
32  * $FreeBSD: src/lib/libc/stdlib/getopt.c,v 1.8 2007/01/09 00:28:10 imp Exp $
33  */
34 
35 #include "namespace.h"
36 #include <stdio.h>
37 #include <stdlib.h>
38 #include <string.h>
39 #include <unistd.h>
40 #include "un-namespace.h"
41 
42 #include "libc_private.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 
53 static char EMSG[] = { '\0' };
54 
55 /*
56  * getopt --
57  *	Parse argc/argv argument vector.
58  */
59 int
60 getopt(int nargc, char * const nargv[], const char *ostr)
61 {
62 	static char *place = EMSG;		/* option letter processing */
63 	char *oli;				/* option letter list index */
64 
65 	/*
66 	 * Some programs like cvs expect optind = 0 to trigger
67 	 * a reset of getopt.
68 	 */
69 	if (optind == 0)
70 		optind = 1;
71 
72 	if (optreset || *place == 0) {		/* update scanning pointer */
73 		optreset = 0;
74 		place = nargv[optind];
75 		if (optind >= nargc || *place++ != '-') {
76 			/* Argument is absent or is not an option */
77 			place = EMSG;
78 			return (-1);
79 		}
80 		optopt = *place++;
81 		if (optopt == '-' && *place == 0) {
82 			/* "--" => end of options */
83 			++optind;
84 			place = EMSG;
85 			return (-1);
86 		}
87 		if (optopt == 0) {
88 			/* Solitary '-', treat as a '-' option
89 			   if the program (eg su) is looking for it. */
90 			place = EMSG;
91 			if (strchr(ostr, '-') == NULL)
92 				return (-1);
93 			optopt = '-';
94 		}
95 	} else
96 		optopt = *place++;
97 
98 	/* See if option letter is one the caller wanted... */
99 	if (optopt == ':' || (oli = strchr(ostr, optopt)) == NULL) {
100 		if (*place == 0)
101 			++optind;
102 		if (opterr && *ostr != ':')
103 			fprintf(stderr,
104 			    "%s: illegal option -- %c\n", _getprogname(),
105 			    optopt);
106 		return (BADCH);
107 	}
108 
109 	/* Does this option need an argument? */
110 	if (oli[1] != ':') {
111 		/* don't need argument */
112 		optarg = NULL;
113 		if (*place == 0)
114 			++optind;
115 	} else {
116 		/* Option-argument is either the rest of this argument or the
117 		   entire next argument. */
118 		if (*place)
119 			optarg = place;
120 		else if (oli[2] == ':')
121 			/*
122 			 * GNU Extension, for optional arguments if the rest of
123 			 * the argument is empty, we return NULL
124 			 */
125 			optarg = NULL;
126 		else if (nargc > ++optind)
127 			optarg = nargv[optind];
128 		else {
129 			/* option-argument absent */
130 			place = EMSG;
131 			if (*ostr == ':')
132 				return (BADARG);
133 			if (opterr)
134 				fprintf(stderr,
135 				    "%s: option requires an argument -- %c\n",
136 				    _getprogname(), optopt);
137 			return (BADCH);
138 		}
139 		place = EMSG;
140 		++optind;
141 	}
142 	return (optopt);			/* return option letter */
143 }
144