fix add.sh + add EEXIST-error

add.sh

@@ -6,20 +6,21 @@ test -d files/ || {
 }
 
 for arg in $@; do
-	arg="$(realpath "$arg")"
-	file="${arg#"$HOME"}"
+	arg="$(realpath -s "$arg")"
+	file="${arg#"$HOME"/}"
 
 	test "$arg" != "$file" || {
-		>&2 echo "$f is not in $HOME"
+		>&2 echo "$file is not in $HOME"
 		continue
 	}
 
-	test -e "files/$file" && {
-    >&2 echo "$f is already added"
+	test ! -e "files/$file" || {
+    >&2 echo "$file is already added"
     continue
 	}
 
 	mkdir -vp "files/$(dirname "$file")"
 	mv -iv "$arg" "files/$file"
 	ln -vfs "$(realpath "files/$file")" "$arg"
+	echo "added"
 done