diff --git a/griddle b/griddle
old mode 100644
new mode 100755
index d83eec5..de6ae1b
--- a/griddle
+++ b/griddle
@@ -1,3 +1,15 @@
 #!/bin/sh
 
-echo "Hello, world"
+main() {
+	if test "$#" -ne 2; then
+		echo "Usage: griddle <inputfile> <outputfile>"
+		return 1
+	fi
+
+	inputfile="$1"
+	outputfile="$2"
+
+	echo "$inputfile" "$outputfile"
+}
+
+main "$@"