diff --git a/util/notegrep/m.py b/util/notegrep/m.py
index 594bc7f..0b6e280 100644
--- a/util/notegrep/m.py
+++ b/util/notegrep/m.py
@@ -7,9 +7,14 @@ class Multi():
         self.files = files
 
     def print_matches(self, patterns, files):
-        for pattern in patterns: print(pattern, end=", ")
+        error = "Invalid input.\nExample: shellnotes -m pattern1,pattern2,pattern3 file1,file2,file3"
+        for pattern in patterns:
+            if pattern == "": return error
+            print(pattern, end=", ")
         print()
-        for file in files: print(file, end=", ")
+        for file in files:
+            if file == "": return error
+            print(file, end=", ")
 
 try:    
     newMulti = Multi(sys.argv[1].split(','), sys.argv[2].split(','))
@@ -17,6 +22,6 @@ try:
 except IndexError:
     patterns = input("Enter patterns, separated by a comma: ")
     files = input("Enter files, separated by a comma: ")
-    newMulti = Multi(patterns, files)
+    newMulti = Multi(patterns.split(','), files.split(','))
     newMulti.print_matches(patterns.split(','), files.split(','))
         
\ No newline at end of file