kiss: rewrite install input

kiss

@@ -1262,18 +1262,20 @@ pkg_install() {
 
     # Install can also take the full path to a tarball. We don't need to check
     # the repository if this is the case.
-    if [ -f "$1" ] && [ -z "${1%%*.tar.*}" ]; then
-        tar_file=$1 pkg_name=${1##*/} pkg_name=${pkg_name%[#@]*}
-
-    elif pkg_cache "$1" 2>/dev/null; then
-        pkg_name=$1
-
-    else
     case $1 in
-            *.tar.*) die "Tarball '$1' does not exist" ;;
-            *)       die "Package '$1' has not yet been built"
+        *.tar.*)
+            [ -f "$1" ] || die "File '$1' does not exist"
+
+            tar_file=$1
+            pkg_name=${1##*/}
+            pkg_name=${pkg_name%@*}
+        ;;
+
+        *)
+            pkg_cache "$1" || die "$1" "Not yet built"
+            pkg_name=$1
+        ;;
     esac
-    fi
 
     mkdir -p "$tar_dir/$pkg_name"
     cd       "$tar_dir/$pkg_name"