chore: refactor tools/create-tarballs.sh to deduplicate code

tools/create-tarballs.sh

@@ -15,16 +15,16 @@
 #    You should have received a copy of the GNU General Public License
 #    along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
-# Create a `lzip` and a `gzip` archive and make a detached GPG signature for them.
+# Create `lzip` and `gzip` archives and make detached GPG signatures for them.
 #
-# When tag name is supplied, it's used to create archive. If there is no tag
+# When tag name is supplied, it's used to create archives. If there is no tag
 # name supplied, latest tag is used.
 
 # Requires:
 #   * GPG
 #   * git
-#   * lzip
 #   * gzip
+#   * lzip
 
 # usage:
 #   ./$script [$tag_name]
@@ -34,33 +34,28 @@
 set -eu -o pipefail
 
 
-archives_from_tag() {
-    git archive --format=tar "$@" \
-    | lzip --best \
-    > "$@".tar.lz
-    echo "$@.tar.lz archive has been created."
-    git archive --format=tar "$@" \
-    | gzip --best \
-    > "$@".tar.gz
-    echo "$@.tar.gz archive has been created."
+archive() {
+    git archive --format=tar "${@%%.tar.*}" \
+    | "${@##*.tar.}"ip --best \
+    > "$@"
+    echo "$@ archive has been created."
 }
 
-sign_archives() {
+sign_archive() {
     gpg \
         --armor \
         --detach-sign \
-        "$@".tar.lz
-    echo "$@.tar.lz.asc signature has been created."
-    gpg \
-        --armor \
-        --detach-sign \
-        "$@".tar.gz
-    echo "$@.tar.gz.asc signature has been created."
+        "$@"
+    echo "$@.asc signature has been created."
 }
 
 create_and_sign() {
-    archives_from_tag "$@"
-    sign_archives "$@"
+    local archives=("$@".tar.{l,g}z)
+    for a in "${archives[@]}"
+    do
+        archive "$a"
+        sign_archive "$a"
+    done
 }
 
 get_tag() {