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+/*
+ * Copyright (c) 1995, 1996, 1997 Kungliga Tekniska Högskolan
+ * (Royal Institute of Technology, Stockholm, Sweden).
+ * 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. Neither the name of the Institute 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 INSTITUTE 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 INSTITUTE 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 <config.h>
+#include <stdlib.h>
+#include <string.h>
+
+#ifndef HAVE_MEMMEM
+#include "roken.h"
+ROKEN_LIB_FUNCTION void * ROKEN_LIB_CALL
+memmem(const void *haystack,
+ size_t haystacklen,
+ const void *needle,
+ size_t needlelen)
+{
+ const unsigned char *hs = haystack;
+ const unsigned char *n = needle;
+ size_t hsi, ni;
+
+ if (haystacklen < needlelen || haystacklen == 0)
+ return NULL;
+ /*
+ * Imagine a haystack of length 5 and needle of length 2, then the largest
+ * index in the haystack at which we can bother looking for the needle is:
+ *
+ * 0 1 2 3 4
+ * +---------+
+ * |?|?|?|?|?|
+ * +---------+
+ * ^
+ * \
+ * here, at index 3, which is 5 - 2, and less than (5 - 2 + 1).
+ */
+ for (hsi = 0, ni = 0; hsi < (haystacklen - needlelen + 1); hsi++, ni = 0) {
+ while (ni < needlelen && n[ni] == hs[hsi + ni])
+ ni++;
+ if (ni == needlelen)
+ return rk_UNCONST(&hs[hsi]);
+ }
+ return NULL;
+}
+#endif