change filenames for possible unifying

files/tar-backup

@@ -9,7 +9,7 @@ import subprocess
 import sys
 from argparse import ArgumentParser
 
-VERSION = "0.0.9"
+VERSION = "0.1.0"
 
 
 class TB:
@@ -256,8 +256,8 @@ def get_opts():
         "--tar-file",
         type=str,
         dest="tar_file",
-        default="backup.tar",
-        help="filename for backups. Use correct extension, e.g. tgz if necessary. Defaults: '%(default)s'",
+        default=None,
+        help="filename for backups. Use correct extension, e.g. tgz if necessary. Defaults to [backup_write_folder].tar",
     )
     parser.add_argument(
         "--ssh-args",
@@ -292,6 +292,10 @@ def get_opts():
     parser.add_argument("backup_source", action="store", help="Source folder to backup with tar+ssh")
     parser.add_argument("base_folder", action="store", help="Local backup folder written to")
     options = parser.parse_args()
+    if options.tar_file is None:
+        options.tar_file = os.path.basename(options.base_folder.rstrip("/")) + ".tar"
+        if options.gpg:
+            options.tar_file += ".gpg"
     if "/" in options.tar_file:
         parser.error("--tar-file must be a filename")
     return options