xref: /dragonfly/lib/libc/stdlib/getopt.c (revision 9f7604d7)
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  * $DragonFly: src/lib/libc/stdlib/getopt.c,v 1.7 2005/11/20 12:37:48 swildner Exp $
34  */
35 
36 #include "namespace.h"
37 #include <stdio.h>
38 #include <stdlib.h>
39 #include <string.h>
40 #include <unistd.h>
41 #include "un-namespace.h"
42 
43 #include "libc_private.h"
44 
45 int	opterr = 1,		/* if error message should be printed */
46 	optind = 1,		/* index into parent argv vector */
47 	optopt,			/* character checked for validity */
48 	optreset;		/* reset getopt */
49 char	*optarg;		/* argument associated with option */
50 
51 #define	BADCH	(int)'?'
52 #define	BADARG	(int)':'
53 
54 static char EMSG[] = { '\0' };
55 
56 /*
57  * getopt --
58  *	Parse argc/argv argument vector.
59  */
60 int
61 getopt(int nargc, char * const nargv[], const char *ostr)
62 {
63 	static char *place = EMSG;		/* option letter processing */
64 	char *oli;				/* option letter list index */
65 
66 	/*
67 	 * Some programs like cvs expect optind = 0 to trigger
68 	 * a reset of getopt.
69 	 */
70 	if (optind == 0)
71 		optind = 1;
72 
73 	if (optreset || *place == 0) {		/* update scanning pointer */
74 		optreset = 0;
75 		place = nargv[optind];
76 		if (optind >= nargc || *place++ != '-') {
77 			/* Argument is absent or is not an option */
78 			place = EMSG;
79 			return (-1);
80 		}
81 		optopt = *place++;
82 		if (optopt == '-' && *place == 0) {
83 			/* "--" => end of options */
84 			++optind;
85 			place = EMSG;
86 			return (-1);
87 		}
88 		if (optopt == 0) {
89 			/* Solitary '-', treat as a '-' option
90 			   if the program (eg su) is looking for it. */
91 			place = EMSG;
92 			if (strchr(ostr, '-') == NULL)
93 				return (-1);
94 			optopt = '-';
95 		}
96 	} else
97 		optopt = *place++;
98 
99 	/* See if option letter is one the caller wanted... */
100 	if (optopt == ':' || (oli = strchr(ostr, optopt)) == NULL) {
101 		if (*place == 0)
102 			++optind;
103 		if (opterr && *ostr != ':')
104 			fprintf(stderr,
105 			    "%s: illegal option -- %c\n", _getprogname(),
106 			    optopt);
107 		return (BADCH);
108 	}
109 
110 	/* Does this option need an argument? */
111 	if (oli[1] != ':') {
112 		/* don't need argument */
113 		optarg = NULL;
114 		if (*place == 0)
115 			++optind;
116 	} else {
117 		/* Option-argument is either the rest of this argument or the
118 		   entire next argument. */
119 		if (*place)
120 			optarg = place;
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 				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