| Jonathan Yong | 9488f91 | 2014-06-10 21:43:05 +0800 | [diff] [blame^] | 1 | /*- |
| 2 | * Copyright (c) 1998 Softweyr LLC. All rights reserved. |
| 3 | * |
| 4 | * strtok_r, from Berkeley strtok |
| 5 | * Oct 13, 1998 by Wes Peters <wes@softweyr.com> |
| 6 | * |
| 7 | * Copyright (c) 1988, 1993 |
| 8 | * The Regents of the University of California. All rights reserved. |
| 9 | * |
| 10 | * Redistribution and use in source and binary forms, with or without |
| 11 | * modification, are permitted provided that the following conditions |
| 12 | * are met: |
| 13 | * 1. Redistributions of source code must retain the above copyright |
| 14 | * notices, this list of conditions and the following disclaimer. |
| 15 | * 2. Redistributions in binary form must reproduce the above copyright |
| 16 | * notices, this list of conditions and the following disclaimer in the |
| 17 | * documentation and/or other materials provided with the distribution. |
| 18 | * 3. Neither the name of the University nor the names of its contributors |
| 19 | * may be used to endorse or promote products derived from this software |
| 20 | * without specific prior written permission. |
| 21 | * |
| 22 | * THIS SOFTWARE IS PROVIDED BY SOFTWEYR LLC, THE REGENTS AND CONTRIBUTORS |
| 23 | * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| 24 | * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A |
| 25 | * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL SOFTWEYR LLC, THE |
| 26 | * REGENTS, OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| 27 | * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED |
| 28 | * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR |
| 29 | * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF |
| 30 | * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING |
| 31 | * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS |
| 32 | * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| 33 | */ |
| 34 | |
| 35 | #define _POSIX_SOURCE 1 |
| 36 | #include <string.h> |
| 37 | |
| 38 | /* |
| 39 | * strtok_r documentation: |
| 40 | * http://pubs.opengroup.org/onlinepubs/009695399/functions/strtok.html |
| 41 | * |
| 42 | * Implementation: |
| 43 | * http://svnweb.freebsd.org/base/head/lib/libc/string/strtok.c?view=co |
| 44 | * |
| 45 | * strtok_r cannot completely be implemented by strtok because of the internal state. |
| 46 | * It breaks when used on 2 strings where they are scanned A, B then A, B. |
| 47 | * Thread-safety is not the issue. |
| 48 | * |
| 49 | * Sample strtok implemenatation, note the internal state: |
| 50 | * char *strtok(char *s, const char *d) { static char *t; return strtok_r(s,d,t); } |
| 51 | * |
| 52 | */ |
| 53 | |
| 54 | char * |
| 55 | strtok_r(char * __restrict s, const char * __restrict delim, char ** __restrict last) |
| 56 | { |
| 57 | char *spanp, *tok; |
| 58 | int c, sc; |
| 59 | |
| 60 | if (s == NULL && (s = *last) == NULL) |
| 61 | return (NULL); |
| 62 | |
| 63 | /* |
| 64 | * Skip (span) leading delimiters (s += strspn(s, delim), sort of). |
| 65 | */ |
| 66 | cont: |
| 67 | c = *s++; |
| 68 | for (spanp = (char *)delim; (sc = *spanp++) != 0;) { |
| 69 | if (c == sc) |
| 70 | goto cont; |
| 71 | } |
| 72 | |
| 73 | if (c == 0) { /* no non-delimiter characters */ |
| 74 | *last = NULL; |
| 75 | return (NULL); |
| 76 | } |
| 77 | tok = s - 1; |
| 78 | |
| 79 | /* |
| 80 | * Scan token (scan for delimiters: s += strcspn(s, delim), sort of). |
| 81 | * Note that delim must have one NUL; we stop if we see that, too. |
| 82 | */ |
| 83 | for (;;) { |
| 84 | c = *s++; |
| 85 | spanp = (char *)delim; |
| 86 | do { |
| 87 | if ((sc = *spanp++) == c) { |
| 88 | if (c == 0) |
| 89 | s = NULL; |
| 90 | else |
| 91 | s[-1] = '\0'; |
| 92 | *last = s; |
| 93 | return (tok); |
| 94 | } |
| 95 | } while (sc != 0); |
| 96 | } |
| 97 | /* NOTREACHED */ |
| 98 | } |
