diff --git a/src b/src
index 29a5172..facdeab 100755
--- a/src
+++ b/src
@@ -28,8 +28,7 @@ add_item() {
 }
 
 rm_item() {
-	## Remove this entry from the srcfile
-	## and delete the source files afterwards
+	## Remove this entry from the srcfile and delete the source files afterwards
 	tmp="$srcfile.tmp"
 
 	awk "\$3 != \"$1\" { print }" "$srcfile" > "$tmp"
@@ -52,8 +51,7 @@ update_gitrepo() {
 }
 
 update_tarfile() {
-	## Download and extract this tarfile if it
-	## doesn't exist yet
+	## Download and extract this tarfile if it doesn't exist yet
 	if ! [ -d "$2" ] ; then
 		wget "$1"
 		tar -xf "$1" -C "$2"
@@ -64,8 +62,7 @@ update_tarfile() {
 }
 
 update_zipfile() {
-	## Download and extract this tarfile if it
-	## doesn't exist yet
+	## Download and extract this zipfile if it doesn't exist yet
 	if ! [ -d "$2" ] ; then
 		wget "$1"
 		unzip "$1" -d "$2"
@@ -150,6 +147,30 @@ list_all() {
 	cleanup
 }
 
+diff_all() {
+	## Show the difference of the sourcefile and the actual content of the
+	## directory
+	preproc
+
+	want=".src_want"
+	actual=".src_actual"
+
+	true > "$want"
+	true > "$actual"
+
+	# Set up want
+	cut -d' ' -f3 < "$tmp" | sort > "$want"
+
+	# Set up actual
+	find . -maxdepth 1 -type d | tail -n +2 | sed 's|^./||' | sort > "$actual"
+
+	# Diff
+	diff -u0 "$want" "$actual"
+
+	rm "$want" "$actual"
+	cleanup
+}
+
 case "$1" in
 	"u"|"update")
 		update_all
@@ -164,6 +185,9 @@ case "$1" in
 	"ls"|"list")
 		list_all
 		;;
+	"d"|"diff")
+		diff_all
+		;;
 	"--help"|"-h")
 		usage
 		exit 1