getsubopt.c revision 330897 
1/*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 1990, 1993
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)
33static char sccsid[] = "@(#)getsubopt.c	8.1 (Berkeley) 6/4/93";
34#endif /* LIBC_SCCS and not lint */
35#include <sys/cdefs.h>
36__FBSDID("$FreeBSD: stable/11/lib/libc/stdlib/getsubopt.c 330897 2018-03-14 03:19:51Z eadler $");
37
38#include <stdlib.h>
39#include <string.h>
40
41/*
42 * The SVID interface to getsubopt provides no way of figuring out which
43 * part of the suboptions list wasn't matched.  This makes error messages
44 * tricky...  The extern variable suboptarg is a pointer to the token
45 * which didn't match.
46 */
47char *suboptarg;
48
49int
50getsubopt(char **optionp, char * const *tokens, char **valuep)
51{
52	int cnt;
53	char *p;
54
55	suboptarg = *valuep = NULL;
56
57	if (!optionp || !*optionp)
58		return(-1);
59
60	/* skip leading white-space, commas */
61	for (p = *optionp; *p && (*p == ',' || *p == ' ' || *p == '\t'); ++p);
62
63	if (!*p) {
64		*optionp = p;
65		return(-1);
66	}
67
68	/* save the start of the token, and skip the rest of the token. */
69	for (suboptarg = p;
70	    *++p && *p != ',' && *p != '=' && *p != ' ' && *p != '\t';);
71
72	if (*p) {
73		/*
74		 * If there's an equals sign, set the value pointer, and
75		 * skip over the value part of the token.  Terminate the
76		 * token.
77		 */
78		if (*p == '=') {
79			*p = '\0';
80			for (*valuep = ++p;
81			    *p && *p != ',' && *p != ' ' && *p != '\t'; ++p);
82			if (*p)
83				*p++ = '\0';
84		} else
85			*p++ = '\0';
86		/* Skip any whitespace or commas after this token. */
87		for (; *p && (*p == ',' || *p == ' ' || *p == '\t'); ++p);
88	}
89
90	/* set optionp for next round. */
91	*optionp = p;
92
93	for (cnt = 0; *tokens; ++tokens, ++cnt)
94		if (!strcmp(suboptarg, *tokens))
95			return(cnt);
96	return(-1);
97}
98