1 /* $NetBSD: stresep.c,v 1.4 2017/08/23 10:27:41 christos Exp $ */ 2 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 #include <sys/cdefs.h> 33 #if defined(LIBC_SCCS) && !defined(lint) 34 #if 0 35 static char sccsid[] = "@(#)strsep.c 8.1 (Berkeley) 6/4/93"; 36 #else 37 __RCSID("$NetBSD: stresep.c,v 1.4 2017/08/23 10:27:41 christos Exp $"); 38 #endif 39 #endif /* LIBC_SCCS and not lint */ 40 41 #include "namespace.h" 42 43 #include <assert.h> 44 #include <string.h> 45 46 #ifdef __weak_alias 47 __weak_alias(stresep,_stresep) 48 #endif 49 50 /* 51 * Get next token from string *stringp, where tokens are possibly-empty 52 * strings separated by characters from delim. If esc is not NUL, then 53 * the characters followed by esc are ignored and are not taken into account 54 * when splitting the string. 55 * 56 * Writes NULs into the string at *stringp to end tokens. 57 * delim need not remain constant from call to call. 58 * On return, *stringp points past the last NUL written (if there might 59 * be further tokens), or is NULL (if there are definitely no more tokens). 60 * 61 * If *stringp is NULL, stresep returns NULL. 62 */ 63 char * 64 stresep(char **stringp, const char *delim, int esc) 65 { 66 char *s; 67 const char *spanp; 68 int c, sc; 69 size_t l; 70 char *tok; 71 72 _DIAGASSERT(stringp != NULL); 73 _DIAGASSERT(delim != NULL); 74 75 if ((s = *stringp) == NULL) 76 return NULL; 77 l = strlen(s) + 1; 78 for (tok = s;;) { 79 c = *s++; 80 l--; 81 while (esc != '\0' && c == esc) { 82 memmove(s - 1, s, l); 83 c = *s++; 84 l--; 85 } 86 spanp = delim; 87 do { 88 if ((sc = *spanp++) == c) { 89 if (c == '\0') 90 s = NULL; 91 else 92 s[-1] = '\0'; 93 *stringp = s; 94 return tok; 95 } 96 } while (sc != '\0'); 97 } 98 } 99