xref: /aosp_15_r20/external/tcpdump/missing/strsep.c (revision 05b00f6010a2396e3db2409989fc67270046269f)
1*05b00f60SXin Li /*-
2*05b00f60SXin Li  * Copyright (c) 1990, 1993
3*05b00f60SXin Li  *	The Regents of the University of California.  All rights reserved.
4*05b00f60SXin Li  *
5*05b00f60SXin Li  * Redistribution and use in source and binary forms, with or without
6*05b00f60SXin Li  * modification, are permitted provided that the following conditions
7*05b00f60SXin Li  * are met:
8*05b00f60SXin Li  * 1. Redistributions of source code must retain the above copyright
9*05b00f60SXin Li  *    notice, this list of conditions and the following disclaimer.
10*05b00f60SXin Li  * 2. Redistributions in binary form must reproduce the above copyright
11*05b00f60SXin Li  *    notice, this list of conditions and the following disclaimer in the
12*05b00f60SXin Li  *    documentation and/or other materials provided with the distribution.
13*05b00f60SXin Li  * 3. All advertising materials mentioning features or use of this software
14*05b00f60SXin Li  *    must display the following acknowledgement:
15*05b00f60SXin Li  *	This product includes software developed by the University of
16*05b00f60SXin Li  *	California, Berkeley and its contributors.
17*05b00f60SXin Li  * 4. Neither the name of the University nor the names of its contributors
18*05b00f60SXin Li  *    may be used to endorse or promote products derived from this software
19*05b00f60SXin Li  *    without specific prior written permission.
20*05b00f60SXin Li  *
21*05b00f60SXin Li  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22*05b00f60SXin Li  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23*05b00f60SXin Li  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24*05b00f60SXin Li  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25*05b00f60SXin Li  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26*05b00f60SXin Li  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27*05b00f60SXin Li  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28*05b00f60SXin Li  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29*05b00f60SXin Li  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30*05b00f60SXin Li  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31*05b00f60SXin Li  * SUCH DAMAGE.
32*05b00f60SXin Li  */
33*05b00f60SXin Li 
34*05b00f60SXin Li #ifdef HAVE_CONFIG_H
35*05b00f60SXin Li #include <config.h>
36*05b00f60SXin Li #endif
37*05b00f60SXin Li 
38*05b00f60SXin Li #include <netdissect-stdinc.h>
39*05b00f60SXin Li 
40*05b00f60SXin Li #include <string.h>
41*05b00f60SXin Li 
42*05b00f60SXin Li #include "netdissect.h"
43*05b00f60SXin Li 
44*05b00f60SXin Li /*
45*05b00f60SXin Li  * Get next token from string *stringp, where tokens are possibly-empty
46*05b00f60SXin Li  * strings separated by characters from delim.
47*05b00f60SXin Li  *
48*05b00f60SXin Li  * Writes NULs into the string at *stringp to end tokens.
49*05b00f60SXin Li  * delim need not remain constant from call to call.
50*05b00f60SXin Li  * On return, *stringp points past the last NUL written (if there might
51*05b00f60SXin Li  * be further tokens), or is NULL (if there are definitely no more tokens).
52*05b00f60SXin Li  *
53*05b00f60SXin Li  * If *stringp is NULL, strsep returns NULL.
54*05b00f60SXin Li  */
55*05b00f60SXin Li char *
strsep(char ** stringp,const char * delim)56*05b00f60SXin Li strsep(char **stringp, const char *delim)
57*05b00f60SXin Li {
58*05b00f60SXin Li 	char *s;
59*05b00f60SXin Li 	const char *spanp;
60*05b00f60SXin Li 	int c, sc;
61*05b00f60SXin Li 	char *tok;
62*05b00f60SXin Li 
63*05b00f60SXin Li 	if ((s = *stringp) == NULL)
64*05b00f60SXin Li 		return (NULL);
65*05b00f60SXin Li 	for (tok = s;;) {
66*05b00f60SXin Li 		c = *s++;
67*05b00f60SXin Li 		spanp = delim;
68*05b00f60SXin Li 		do {
69*05b00f60SXin Li 			if ((sc = *spanp++) == c) {
70*05b00f60SXin Li 				if (c == 0)
71*05b00f60SXin Li 					s = NULL;
72*05b00f60SXin Li 				else
73*05b00f60SXin Li 					s[-1] = 0;
74*05b00f60SXin Li 				*stringp = s;
75*05b00f60SXin Li 				return (tok);
76*05b00f60SXin Li 			}
77*05b00f60SXin Li 		} while (sc != 0);
78*05b00f60SXin Li 	}
79*05b00f60SXin Li 	/* NOTREACHED */
80*05b00f60SXin Li }
81