diff options
Diffstat (limited to 'gnu/libexec/uucp/libuucp/strstr.c')
| -rw-r--r-- | gnu/libexec/uucp/libuucp/strstr.c | 55 |
1 files changed, 55 insertions, 0 deletions
diff --git a/gnu/libexec/uucp/libuucp/strstr.c b/gnu/libexec/uucp/libuucp/strstr.c new file mode 100644 index 000000000000..111460b11d3c --- /dev/null +++ b/gnu/libexec/uucp/libuucp/strstr.c @@ -0,0 +1,55 @@ +/* Copyright (C) 1991, 1992 Free Software Foundation, Inc. +This file is part of the GNU C Library. + +The GNU C Library is free software; you can redistribute it and/or +modify it under the terms of the GNU Library General Public License as +published by the Free Software Foundation; either version 2 of the +License, or (at your option) any later version. + +The GNU C Library is distributed in the hope that it will be useful, +but WITHOUT ANY WARRANTY; without even the implied warranty of +MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU +Library General Public License for more details. + +You should have received a copy of the GNU Library General Public +License along with the GNU C Library; see the file COPYING.LIB. If +not, write to the Free Software Foundation, Inc., 675 Mass Ave, +Cambridge, MA 02139, USA. + +This file was modified slightly by Ian Lance Taylor, May 1992, for +Taylor UUCP. */ + +#include "uucp.h" + +/* Return the first ocurrence of NEEDLE in HAYSTACK. */ +char * +strstr (haystack, needle) + const char *const haystack; + const char *const needle; +{ + register const char *const needle_end = strchr(needle, '\0'); + register const char *const haystack_end = strchr(haystack, '\0'); + register const size_t needle_len = needle_end - needle; + register const size_t needle_last = needle_len - 1; + register const char *begin; + + if (needle_len == 0) + return (char *) haystack_end; + if ((size_t) (haystack_end - haystack) < needle_len) + return NULL; + + for (begin = &haystack[needle_last]; begin < haystack_end; ++begin) + { + register const char *n = &needle[needle_last]; + register const char *h = begin; + do + if (*h != *n) + goto loop; + while (--n >= needle && --h >= haystack); + + return (char *) h; + loop:; + } + + return NULL; +} |
