1 files changed, 25 insertions, 0 deletions
diff --git a/lib9/cistrcmp.c b/lib9/cistrcmp.c
new file mode 100644
index 00000000..fc7d84e4
--- /dev/null
+++ b/lib9/cistrcmp.c
@@ -0,0 +1,25 @@
+#include "lib9.h"
+
+int
+cistrcmp(char *s1, char *s2)
+{
+	int c1, c2;
+
+	while(*s1){
+		c1 = *(uchar*)s1++;
+		c2 = *(uchar*)s2++;
+
+		if(c1 == c2)
+			continue;
+
+		if(c1 >= 'A' && c1 <= 'Z')
+			c1 -= 'A' - 'a';
+
+		if(c2 >= 'A' && c2 <= 'Z')
+			c2 -= 'A' - 'a';
+
+		if(c1 != c2)
+			return c1 - c2;
+	}
+	return -*s2;
+}