diff --git a/erc b/erc
index 3f51592..f03d049 100644
--- a/erc
+++ b/erc
@@ -30,7 +30,12 @@ end
 
 keys["!"] = function()
   command = prompt("shell command: %s")
-  command = string.gsub(command, "%$", get_filename())
+
+  if command == nil then
+    return
+  end
+
+  command = string.gsub(command, "%$", get_filename() or "")
   handle = io.popen(command)
   result = handle:read("*a")
   handle:close()
@@ -41,6 +46,12 @@ end
 
 meta_commands["carp"] = function()
   file = get_filename()
+
+  if file == nil then
+    message("File has no name!")
+    return
+  end
+
   handle = io.popen("carp --check "..file)
   result = handle:read("*a")
   handle:close()
@@ -56,7 +67,7 @@ meta_commands["carp"] = function()
 
   f, l, c, msg = string.match(result, "([^:]+):(%d+):(%d+) (.-)[\r\n].*")
 
-  if f == file then
+  if string.match(f, file) then
     move(tonumber(l)-1, tonumber(c))
     message(msg)
   end