1 files changed, 73 insertions, 0 deletions
diff --git a/missing/strstr.c b/missing/strstr.c
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+++ b/missing/strstr.c
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+/* 
+ * strstr.c --
+ *
+ *	Source code for the "strstr" library routine.
+ *
+ * Copyright 1988-1991 Regents of the University of California
+ * Permission to use, copy, modify, and distribute this
+ * software and its documentation for any purpose and without
+ * fee is hereby granted, provided that the above copyright
+ * notice appears in all copies.  The University of California
+ * makes no representations about the suitability of this
+ * software for any purpose.  It is provided "as is" without
+ * express or implied warranty.
+ */
+
+#ifndef lint
+static char rcsid[] = "$Header: /work/cvsroot/ruby/missing/strstr.c,v 1.1 1994/06/27 15:49:21 matz Exp $ SPRITE (Berkeley)";
+#endif /* not lint */
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * strstr --
+ *
+ *	Locate the first instance of a substring in a string.
+ *
+ * Results:
+ *	If string contains substring, the return value is the
+ *	location of the first matching instance of substring
+ *	in string.  If string doesn't contain substring, the
+ *	return value is 0.  Matching is done on an exact
+ *	character-for-character basis with no wildcards or special
+ *	characters.
+ *
+ * Side effects:
+ *	None.
+ *
+ *----------------------------------------------------------------------
+ */
+
+char *
+strstr(string, substring)
+    register char *string;	/* String to search. */
+    char *substring;		/* Substring to try to find in string. */
+{
+    register char *a, *b;
+
+    /* First scan quickly through the two strings looking for a
+     * single-character match.  When it's found, then compare the
+     * rest of the substring.
+     */
+
+    b = substring;
+    if (*b == 0) {
+	return string;
+    }
+    for ( ; *string != 0; string += 1) {
+	if (*string != *b) {
+	    continue;
+	}
+	a = string;
+	while (1) {
+	    if (*b == 0) {
+		return string;
+	    }
+	    if (*a++ != *b++) {
+		break;
+	    }
+	}
+	b = substring;
+    }
+    return (char *) 0;
+}