1 /* 2 * Copyright (c) 1988 Regents of the University of California. 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms are permitted 6 * provided that the above copyright notice and this paragraph are 7 * duplicated in all such forms and that any documentation, 8 * advertising materials, and other materials related to such 9 * distribution and use acknowledge that the software was developed 10 * by the University of California, Berkeley. The name of the 11 * University may not be used to endorse or promote products derived 12 * from this software without specific prior written permission. 13 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR 14 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED 15 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE. 16 */ 17 18 #if defined(LIBC_SCCS) && !defined(lint) 19 static char sccsid[] = "@(#)strtok.c 5.6 (Berkeley) 05/17/90"; 20 #endif /* LIBC_SCCS and not lint */ 21 22 #include <stddef.h> 23 #include <string.h> 24 25 char * 26 strtok(s, delim) 27 register char *s, *delim; 28 { 29 register char *spanp; 30 register int c, sc; 31 char *tok; 32 static char *last; 33 34 35 if (s == NULL && (s = last) == NULL) 36 return (NULL); 37 38 /* 39 * Skip (span) leading delimiters (s += strspn(s, delim), sort of). 40 */ 41 cont: 42 c = *s++; 43 for (spanp = delim; (sc = *spanp++) != 0;) { 44 if (c == sc) 45 goto cont; 46 } 47 48 if (c == 0) { /* no non-delimiter characters */ 49 last = NULL; 50 return (NULL); 51 } 52 tok = s - 1; 53 54 /* 55 * Scan token (scan for delimiters: s += strcspn(s, delim), sort of). 56 * Note that delim must have one NUL; we stop if we see that, too. 57 */ 58 for (;;) { 59 c = *s++; 60 spanp = delim; 61 do { 62 if ((sc = *spanp++) == c) { 63 if (c == 0) 64 s = NULL; 65 else 66 s[-1] = 0; 67 last = s; 68 return (tok); 69 } 70 } while (sc != 0); 71 } 72 /* NOTREACHED */ 73 } 74