xref: /freebsd/contrib/libpcap/missing/getopt.c (revision 2b833162)
1 /*
2  * Copyright (c) 1987, 1993, 1994
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. All advertising materials mentioning features or use of this software
14  *    must display the following acknowledgement:
15  *	This product includes software developed by the University of
16  *	California, Berkeley and its contributors.
17  * 4. Neither the name of the University nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  */
33 
34 #if defined(LIBC_SCCS) && !defined(lint)
35 static char sccsid[] = "@(#)getopt.c	8.3 (Berkeley) 4/27/95";
36 #endif /* LIBC_SCCS and not lint */
37 
38 #include <stdio.h>
39 #include <stdlib.h>
40 #include <string.h>
41 
42 #include "getopt.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 #define	EMSG	""
53 
54 /*
55  * getopt --
56  *	Parse argc/argv argument vector.
57  */
58 int
59 getopt(int nargc, char * const *nargv, const char *ostr)
60 {
61 	char *cp;
62 	static char *__progname;
63 	static char *place = EMSG;		/* option letter processing */
64 	char *oli;				/* option letter list index */
65 
66 	if (__progname == NULL) {
67 		if ((cp = strrchr(nargv[0], '/')) != NULL)
68 			__progname = cp + 1;
69 		else
70 			__progname = nargv[0];
71 	}
72 	if (optreset || !*place) {		/* update scanning pointer */
73 		optreset = 0;
74 		if (optind >= nargc || *(place = nargv[optind]) != '-') {
75 			place = EMSG;
76 			return (-1);
77 		}
78 		if (place[1] && *++place == '-') {	/* found "--" */
79 			++optind;
80 			place = EMSG;
81 			return (-1);
82 		}
83 	}
84 	optopt = (int)*place++;
85 	if (optopt == (int)':') {		/* option letter okay? */
86 		if (!*place)
87 			++optind;
88 		if (opterr && *ostr != ':')
89 			(void)fprintf(stderr,
90 			    "%s: illegal option -- %c\n", __progname, optopt);
91 		return (BADCH);
92 	}
93 	oli = strchr(ostr, optopt);
94 	if (!oli) {
95 		/*
96 		 * if the user didn't specify '-' as an option,
97 		 * assume it means -1.
98 		 */
99 		if (optopt == (int)'-')
100 			return (-1);
101 		if (!*place)
102 			++optind;
103 		if (opterr && *ostr != ':')
104 			(void)fprintf(stderr,
105 			    "%s: illegal option -- %c\n", __progname, optopt);
106 		return (BADCH);
107 	}
108 	if (*++oli != ':') {			/* don't need argument */
109 		optarg = NULL;
110 		if (!*place)
111 			++optind;
112 	}
113 	else {					/* need an argument */
114 		if (*place)			/* no white space */
115 			optarg = place;
116 		else if (nargc <= ++optind) {	/* no arg */
117 			place = EMSG;
118 			if (*ostr == ':')
119 				return (BADARG);
120 			if (opterr)
121 				(void)fprintf(stderr,
122 				    "%s: option requires an argument -- %c\n",
123 				    __progname, optopt);
124 			return (BADCH);
125 		}
126 		else				/* white space */
127 			optarg = nargv[optind];
128 		place = EMSG;
129 		++optind;
130 	}
131 	return (optopt);			/* dump back option letter */
132 }
133