strtok.c
上传用户:tsgydb
上传日期:2007-04-14
资源大小:10674k
文件大小:3k
- /*
- * Copyright (c) 1988 Regents of the University of California.
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- * 1. Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- * 2. Redistributions in binary form must reproduce the above copyright
- * notice, this list of conditions and the following disclaimer in the
- * documentation and/or other materials provided with the distribution.
- * 3. All advertising materials mentioning features or use of this software
- * must display the following acknowledgement:
- * This product includes software developed by the University of
- * California, Berkeley and its contributors.
- * 4. Neither the name of the University nor the names of its contributors
- * may be used to endorse or promote products derived from this software
- * without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
- * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
- * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
- * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
- * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
- * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
- * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
- * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
- * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
- * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
- * SUCH DAMAGE.
- */
- #if defined(LIBC_SCCS) && !defined(lint)
- /*static char *sccsid = "from: @(#)strtok.c 5.8 (Berkeley) 2/24/91";*/
- static char *rcsid = "$Id$";
- #endif /* LIBC_SCCS and not lint */
- #include <pthread.h>
- #include <string.h>
- #include <stdlib.h>
- char *
- strtok(s, delim)
- register char *s;
- register const char *delim;
- {
- static pthread_mutex_t strtok_mutex = PTHREAD_MUTEX_INITIALIZER;
- static pthread_key_t strtok_key = -1;
- char **lasts;
- pthread_mutex_lock(&strtok_mutex);
- if (strtok_key < 0) {
- if (pthread_key_create(&strtok_key, free) < 0) {
- pthread_mutex_unlock(&strtok_mutex);
- return(NULL);
- }
- }
- pthread_mutex_unlock(&strtok_mutex);
- if ((lasts = pthread_getspecific(strtok_key)) == NULL) {
- if ((lasts = (char **)malloc(sizeof(char *))) == NULL) {
- return(NULL);
- }
- pthread_setspecific(strtok_key, lasts);
- }
- return(strtok_r(s, delim, lasts));
- }
- char *
- strtok_r(s, delim, lasts)
- register char *s;
- register const char *delim;
- register char **lasts;
- {
- register char *spanp;
- register int c, sc;
- char *tok;
- if (s == NULL && (s = *lasts) == NULL)
- return (NULL);
- /*
- * Skip (span) leading delimiters (s += strspn(s, delim), sort of).
- */
- cont:
- c = *s++;
- for (spanp = (char *)delim; (sc = *spanp++) != 0;) {
- if (c == sc)
- goto cont;
- }
- if (c == 0) { /* no non-delimiter characters */
- *lasts = NULL;
- return (NULL);
- }
- tok = s - 1;
- /*
- * Scan token (scan for delimiters: s += strcspn(s, delim), sort of).
- * Note that delim must have one NUL; we stop if we see that, too.
- */
- for (;;) {
- c = *s++;
- spanp = (char *)delim;
- do {
- if ((sc = *spanp++) == c) {
- if (c == 0)
- s = NULL;
- else
- s[-1] = 0;
- *lasts = s;
- return (tok);
- }
- } while (sc != 0);
- }
- /* NOTREACHED */
- }