1 /* $Id: getopt.c,v 1.3 2009-01-22 20:53:07 fwarmerdam 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 0
33 static char sccsid[] = "@(#)getopt.c	8.3 (Berkeley) 4/27/95";
34 __RCSID("$NetBSD: getopt.c,v 1.26 2003/08/07 16:43:40 agc Exp $");
35 #endif
36 
37 #include <stdio.h>
38 #include <string.h>
39 #include "libport.h"
40 
41 int	opterr = 1,		/* if error message should be printed */
42 	optind = 1,		/* index into parent argv vector */
43 	optopt,			/* character checked for validity */
44 	optreset;		/* reset getopt */
45 char	*optarg;		/* argument associated with option */
46 
47 #define	BADCH	(int)'?'
48 #define	BADARG	(int)':'
49 #define	EMSG	""
50 
51 /*
52  * getopt --
53  *	Parse argc/argv argument vector.
54  */
55 int
getopt(int argc,char * const argv[],const char * optstring)56 getopt(int argc, char * const argv[], const char *optstring)
57 {
58 	static char *place = EMSG;		/* option letter processing */
59 	char *oli;				/* option letter list index */
60 
61 	if (optreset || *place == 0) {		/* update scanning pointer */
62 		optreset = 0;
63 		place = argv[optind];
64 		if (optind >= argc || *place++ != '-') {
65 			/* Argument is absent or is not an option */
66 			place = EMSG;
67 			return (-1);
68 		}
69 		optopt = *place++;
70 		if (optopt == '-' && *place == 0) {
71 			/* "--" => end of options */
72 			++optind;
73 			place = EMSG;
74 			return (-1);
75 		}
76 		if (optopt == 0) {
77 			/* Solitary '-', treat as a '-' option
78 			   if the program (eg su) is looking for it. */
79 			place = EMSG;
80 			if (strchr(optstring, '-') == NULL)
81 				return -1;
82 			optopt = '-';
83 		}
84 	} else
85 		optopt = *place++;
86 
87 	/* See if option letter is one the caller wanted... */
88 	if (optopt == ':' || (oli = strchr(optstring, optopt)) == NULL) {
89 		if (*place == 0)
90 			++optind;
91 		if (opterr && *optstring != ':')
92 			(void)fprintf(stderr,
93                                       "unknown option -- %c\n", optopt);
94 		return (BADCH);
95 	}
96 
97 	/* Does this option need an argument? */
98 	if (oli[1] != ':') {
99 		/* don't need argument */
100 		optarg = NULL;
101 		if (*place == 0)
102 			++optind;
103 	} else {
104 		/* Option-argument is either the rest of this argument or the
105 		   entire next argument. */
106 		if (*place)
107 			optarg = place;
108 		else if (argc > ++optind)
109 			optarg = argv[optind];
110 		else {
111 			/* option-argument absent */
112 			place = EMSG;
113 			if (*optstring == ':')
114 				return (BADARG);
115 			if (opterr)
116 				(void)fprintf(stderr,
117                                         "option requires an argument -- %c\n",
118                                         optopt);
119 			return (BADCH);
120 		}
121 		place = EMSG;
122 		++optind;
123 	}
124 	return (optopt);			/* return option letter */
125 }
126