xref: /freebsd/contrib/tcpdump/missing/strsep.c (revision 0a7e5f1f02aad2ff5fff1c60f44c6975fd07e1d9)
1 /*-
2  * Copyright (c) 1990, 1993
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 #include <config.h>
35 
36 #include <netdissect-stdinc.h>
37 
38 #include <string.h>
39 
40 #include "netdissect.h"
41 
42 /*
43  * Get next token from string *stringp, where tokens are possibly-empty
44  * strings separated by characters from delim.
45  *
46  * Writes NULs into the string at *stringp to end tokens.
47  * delim need not remain constant from call to call.
48  * On return, *stringp points past the last NUL written (if there might
49  * be further tokens), or is NULL (if there are definitely no more tokens).
50  *
51  * If *stringp is NULL, strsep returns NULL.
52  */
53 char *
strsep(char ** stringp,const char * delim)54 strsep(char **stringp, const char *delim)
55 {
56 	char *s;
57 	const char *spanp;
58 	int c, sc;
59 	char *tok;
60 
61 	if ((s = *stringp) == NULL)
62 		return (NULL);
63 	for (tok = s;;) {
64 		c = *s++;
65 		spanp = delim;
66 		do {
67 			if ((sc = *spanp++) == c) {
68 				if (c == 0)
69 					s = NULL;
70 				else
71 					s[-1] = 0;
72 				*stringp = s;
73 				return (tok);
74 			}
75 		} while (sc != 0);
76 	}
77 	/* NOTREACHED */
78 }
79