summaryrefslogtreecommitdiff
path: root/openbsd-compat
diff options
context:
space:
mode:
authorDarren Tucker <dtucker@dtucker.net>2019-07-16 09:07:18 +1000
committerDarren Tucker <dtucker@dtucker.net>2019-07-16 09:07:18 +1000
commitc7bd4617293a903bd3fac3394a7e72d439af49a5 (patch)
treed1f85be84997bf6af62c0e55b7376273470d2fce /openbsd-compat
parent477e2a3be8b10df76e8d76f0427b043280d73d68 (diff)
Import memmem.c from OpenBSD.
Diffstat (limited to 'openbsd-compat')
-rw-r--r--openbsd-compat/memmem.c64
1 files changed, 64 insertions, 0 deletions
diff --git a/openbsd-compat/memmem.c b/openbsd-compat/memmem.c
new file mode 100644
index 00000000..823443b0
--- /dev/null
+++ b/openbsd-compat/memmem.c
@@ -0,0 +1,64 @@
+/* $OpenBSD: memmem.c,v 1.4 2015/08/31 02:53:57 guenther Exp $ */
+/*-
+ * Copyright (c) 2005 Pascal Gloor <pascal.gloor@spale.com>
+ *
+ * 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. The name of the author may not be used to endorse or promote
+ * products derived from this software without specific prior written
+ * permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
+ */
+
+#include <string.h>
+
+/*
+ * Find the first occurrence of the byte string s in byte string l.
+ */
+
+void *
+memmem(const void *l, size_t l_len, const void *s, size_t s_len)
+{
+ const char *cur, *last;
+ const char *cl = l;
+ const char *cs = s;
+
+ /* a zero length needle should just return the haystack */
+ if (s_len == 0)
+ return (void *)cl;
+
+ /* "s" must be smaller or equal to "l" */
+ if (l_len < s_len)
+ return NULL;
+
+ /* special case where s_len == 1 */
+ if (s_len == 1)
+ return memchr(l, *cs, l_len);
+
+ /* the last position where its possible to find "s" in "l" */
+ last = cl + l_len - s_len;
+
+ for (cur = cl; cur <= last; cur++)
+ if (cur[0] == cs[0] && memcmp(cur, cs, s_len) == 0)
+ return (void *)cur;
+
+ return NULL;
+}
+DEF_WEAK(memmem);