a

libc/runestrstr.c

@@ -0,0 +1,29 @@
+#include <u.h>
+#include <libc.h>
+
+/*
+ * Return pointer to first occurrence of s2 in s1,
+ * 0 if none
+ */
+Rune*
+runestrstr(Rune *s1, Rune *s2)
+{
+	Rune *p, *pa, *pb;
+	int c0, c;
+
+	c0 = *s2;
+	if(c0 == 0)
+		return s1;
+	s2++;
+	for(p=runestrchr(s1, c0); p; p=runestrchr(p+1, c0)) {
+		pa = p;
+		for(pb=s2;; pb++) {
+			c = *pb;
+			if(c == 0)
+				return p;
+			if(c != *++pa)
+				break;
+		}
+	}
+	return 0;
+}