1 files changed, 25 insertions, 0 deletions
diff --git a/lib9/utfnlen.c b/lib9/utfnlen.c
new file mode 100644
index 00000000..02623f51
--- /dev/null
+++ b/lib9/utfnlen.c
@@ -0,0 +1,25 @@
+#include "lib9.h"
+
+int
+utfnlen(char *s, long m)
+{
+	int c;
+	long n;
+	Rune rune;
+	char *es;
+
+	es = s + m;
+	for(n = 0; s < es; n++) {
+		c = *(uchar*)s;
+		if(c < Runeself){
+			if(c == '\0')
+				break;
+			s++;
+			continue;
+		}
+		if(!fullrune(s, es-s))
+			break;
+		s += chartorune(&rune, s);
+	}
+	return n;
+}