1 /* $NetBSD: strtok.c,v 1.11 2003/08/07 16:43:53 agc Exp $ */ 2 3 /* 4 * Copyright (c) 1988, 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 #include <sys/cdefs.h> 33 #if defined(LIBC_SCCS) && !defined(lint) 34 #if 0 35 static char sccsid[] = "@(#)strtok.c 8.1 (Berkeley) 6/4/93"; 36 #else 37 __RCSID("$NetBSD: strtok.c,v 1.11 2003/08/07 16:43:53 agc Exp $"); 38 #endif 39 #endif /* LIBC_SCCS and not lint */ 40 41 #include <assert.h> 42 #include <string.h> 43 44 char * 45 strtok(s, delim) 46 char *s; 47 const char *delim; 48 { 49 const char *spanp; 50 int c, sc; 51 char *tok; 52 static char *last; 53 54 /* s may be NULL */ 55 _DIAGASSERT(delim != NULL); 56 57 if (s == NULL && (s = last) == NULL) 58 return (NULL); 59 60 /* 61 * Skip (span) leading delimiters (s += strspn(s, delim), sort of). 62 */ 63 cont: 64 c = *s++; 65 for (spanp = delim; (sc = *spanp++) != 0;) { 66 if (c == sc) 67 goto cont; 68 } 69 70 if (c == 0) { /* no non-delimiter characters */ 71 last = NULL; 72 return (NULL); 73 } 74 tok = s - 1; 75 76 /* 77 * Scan token (scan for delimiters: s += strcspn(s, delim), sort of). 78 * Note that delim must have one NUL; we stop if we see that, too. 79 */ 80 for (;;) { 81 c = *s++; 82 spanp = delim; 83 do { 84 if ((sc = *spanp++) == c) { 85 if (c == 0) 86 s = NULL; 87 else 88 s[-1] = 0; 89 last = s; 90 return (tok); 91 } 92 } while (sc != 0); 93 } 94 /* NOTREACHED */ 95 } 96