diff --git a/sh/core/code.awk b/sh/core/code.awk
index 033fb47..ca712ae 100644
--- a/sh/core/code.awk
+++ b/sh/core/code.awk
@@ -58,6 +58,12 @@ function extract(string, type) {
 	}
 }
 
+function remove_first(string, target, tmp) {
+	tmp = string
+	sub(target, "", tmp)
+	return trim(tmp)
+}
+
 function trim(string) {
 	text = string
 	sub("^[\t ]*", "", text)
@@ -106,34 +112,26 @@ function parse(string) {
 	# module
 	if (match(string, RE_MODULE)) {
 		current_match = "module"
-		module = string
-		sub("#\\.", "", module)
+		module = remove_first(string, "#\\.")
 		doc_reset()
-		module = trim(module)
 		shebang = ""
 
 	# shebang
 	} else if (match(string, RE_SHEBANG)) {
 		current_match = "shebang"
-		shebang = string
-		sub("#!", "", shebang)
-		shebang = trim(shebang)
+		shebang = remove_first(string, "#!")
 
 	# alias
 	} else if (match(string, re["alias"])) {
 		current_match = "alias"
-		alias = string
-		sub("#=", "", alias)
-		alias = trim(alias)
+		alias = remove_first(string, "#=")
 		aliases[alias] = ""
 		doc_append("= " alias)
 
 	# command
 	} else if (match(string, re["command"])) {
 		current_match = "command"
-		command = string
-		sub("#/", "", command)
-		command = trim(command)
+		command = remove_first(string, "#/")
 		commands[command] = ""
 		doc_append("/ " command)