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+/*
+ * strstr.c -- return the offset of one string within another.
+ *
+ * Copyright (C) 1997 Free Software Foundation, Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 2, or (at your option) any later
+ * version.
+ *
+ * This program 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 General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; if not, write to the Free Software Foundation, Inc., 59
+ * Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ */
+
+/* Written by Philippe De Muyter <phdm@info.ucl.ac.be>. */
+
+/*
+ * NAME
+ *
+ * strstr -- locate first occurence of a substring
+ *
+ * SYNOPSIS
+ *
+ * char *strstr (char *s1, char *s2)
+ *
+ * DESCRIPTION
+ *
+ * Locates the first occurence in the string pointed to by S1 of the string
+ * pointed to by S2. Returns a pointer to the substring found, or a NULL
+ * pointer if not found. If S2 points to a string with zero length, the
+ * function returns S1.
+ *
+ * BUGS
+ *
+ */
+
+char *
+strstr (buf, sub)
+ register char *buf;
+ register char *sub;
+{
+ register char *bp;
+
+ if (!*sub)
+ return buf;
+ for (;;)
+ {
+ if (!*buf)
+ break;
+ bp = buf;
+ for (;;)
+ {
+ if (!*sub)
+ return buf;
+ if (*bp++ != *sub++)
+ break;
+ }
+ sub -= (unsigned long) bp;
+ sub += (unsigned long) buf;
+ buf += 1;
+ }
+ return 0;
+}
+