Add linecmp()
diff --git a/libutil/linecmp.c b/libutil/linecmp.c
new file mode 100644
index 0000000..cba27d1
--- /dev/null
+++ b/libutil/linecmp.c
@@ -0,0 +1,20 @@
+/* See LICENSE file for copyright and license details. */
+#include <stdio.h>
+#include <string.h>
+
+#include "../text.h"
+#include "../util.h"
+
+int
+linecmp(struct line *a, struct line *b)
+{
+ int res = 0;
+
+ if (!(res = memcmp(a->data, b->data, MIN(a->len, b->len))) &&
+ a->len != b->len) {
+ res = a->data[MIN(a->len, b->len) - 1] -
+ b->data[MIN(a->len, b->len) - 1];
+ }
+
+ return res;
+}
