cli: "show --usage" to display physical disk usage per backup

CHANGELOG.md

@@ -28,6 +28,7 @@ General Public License v2 (GPLv2). See LICENSES directory or go to
   ([PR#2486](https://github.com/bit-team/backintime/pull/2486))
 - Dependency(build): `pandoc` to convert markdown changelog into HTML
 - Dependency(runtime-cli): `gocryptfs`
+- CLI option '--usage' to 'show' subcommand to display the total physical disk usage of all backups in a profile
 
 ### Removed
 - **Breaking**: EncFS support including existing EncFS profiles
@@ -42,9 +43,6 @@ General Public License v2 (GPLv2). See LICENSES directory or go to
 ## Fixed
 - Prevent crash in case a plugin fails ([#2447](https://github.com/bit-team/backintime/issues/2447))
 
-## Fixed
-- Prevent Back In Time crash when a plugin fails ([#2447](https://github.com/bit-team/backintime/issues/2447))
-
 ## [1.6.1] (2026-02-10)
 
 ### Fixed

common/cliarguments.py

@@ -682,6 +682,12 @@ def _create_cmd_show(self):
             default=False,
             help='show the last (youngest) backup only')
 
+        parser.add_argument(
+            '--usage',
+            action='store_true',
+            default=False,
+            help='display total physical disk usage of all backups')
+
         self.parsers[name] = parser
 
     def _create_cmd_unmount(self):

common/clicommands.py

@@ -14,6 +14,7 @@
 """Module about CLI commands"""
 import sys
 import argparse
+import subprocess
 from datetime import datetime
 from time import sleep
 import tools
@@ -29,6 +30,7 @@
 from mount import MountManager
 from applicationinstance import ApplicationInstance
 from shutdownagent import ShutdownAgent
+from storagesize import StorageSize, SizeUnit
 
 
 def _deprecation_msg(cmd_flag: str, replacement: str) -> str:
@@ -511,9 +513,18 @@ def show_backups(args: argparse.Namespace):
             mounted_path=mount_manager.path
         )
 
+    if not backups:
+        logger.error(f'No backups in profile "{cfg.profileName()}"')
+        _umount(cfg)
+        sys.exit(bitbase.RETURN_ERR)
+
     if args.last:
         backups = backups[-1:]
 
+    if args.usage:
+        size_bytes = _compute_total_usage(cfg, backups)
+        print(_format_usage(size_bytes))
+
     if args.path:
         # Path
         def _element(e):
@@ -530,10 +541,6 @@ def _element(e):
 
     print(result)
 
-    if not backups:
-        logger.info(f'No backups in profile "{cfg.profileName()}"')
-        sys.exit(bitbase.RETURN_ERR)
-
     sys.exit(bitbase.RETURN_OK)
 
 
@@ -579,19 +586,77 @@ def prune(args: argparse.Namespace):
         sys.exit(bitbase.RETURN_OK)
 
 
-def unmount(args):
-    """Unmount all filesystems.
-
-    Args:
-        args: Previously parsed arguments
-
-    Raises:
-        SystemExit: 0
-    """
-    cli.set_quiet(args)
-
-    cfg = _get_config(args)
+def _du_local_total(paths: list) -> int:
+    if not paths:
+        return 0
+    try:
+        result = subprocess.run(
+            ['du', '-sbc'] + [str(p) for p in paths],
+            capture_output=True, text=True, check=True
+        )
+        total_line = result.stdout.strip().split('\n')[-1]
+        return int(total_line.split()[0])
+    except subprocess.CalledProcessError as err:
+        logger.error(
+            f'Failed to compute local disk usage: {err.stderr.strip()}')
+        return -1
+    except (ValueError, IndexError):
+        logger.error('Failed to parse disk usage output')
+        return -1
+
+
+def _du_remote_total(cfg, backups) -> int:
+    mode = cfg.snapshotsMode()
+    remote_paths = []
+
+    for sid_str, _ in backups:
+        sid_obj = snapshots.SID(sid_str, cfg)
+        if mode == 'ssh_encfs':
+            remote_path = sid_obj.path(use_mode=['ssh_encfs'])
+        else:
+            remote_path = sid_obj.path(use_mode=['ssh'])
+        remote_paths.append(remote_path)
 
-    mount_manager = MountManager.create(cfg)
-    with mount_manager.mounted():
-        sys.exit(bitbase.RETURN_OK)
+    ssh_cmd = cfg.sshCommand(
+        cmd=['du', '-sbc'] + remote_paths,
+        nice=False, ionice=False
+    )
+    try:
+        result = subprocess.run(
+            ssh_cmd, capture_output=True, text=True, check=True
+        )
+        total_line = result.stdout.strip().split('\n')[-1]
+        return int(total_line.split()[0])
+    except subprocess.CalledProcessError as err:
+        logger.error(
+            f'Failed to compute remote disk usage: {err.stderr.strip()}')
+        return -1
+    except (ValueError, IndexError):
+        logger.error('Failed to parse remote disk usage output')
+        return -1
+
+
+def _compute_total_usage(cfg, backups):
+    mode = cfg.snapshotsMode()
+    if mode in ('ssh', 'ssh_encfs'):
+        return _du_remote_total(cfg, backups)
+    return _du_local_total([p for _, p in backups])
+
+
+def _format_usage(size_bytes: int) -> str:
+    if size_bytes < 0:
+        return 'Total disk usage: ERROR (could not determine size)'
+
+    size = StorageSize(size_bytes)
+
+    if size >= StorageSize(1, SizeUnit.GIB):
+        value = size.value(SizeUnit.GIB, decimal_places=1)
+        return f'Total disk usage: {value:.1f} GiB'
+    elif size >= StorageSize(1, SizeUnit.MIB):
+        value = size.value(SizeUnit.MIB, decimal_places=1)
+        return f'Total disk usage: {value:.1f} MiB'
+    elif size_bytes >= 1024:
+        value = size_bytes / 1024
+        return f'Total disk usage: {value:.1f} KiB'
+    else:
+        return f'Total disk usage: {size_bytes} Byte'

common/test/test_args.py

@@ -231,3 +231,31 @@ def test_local_backup_and_no_local_backup(self):
                 ('restore', '--local-backup', '--no-local-backup'),
                 self.parser_agent
             )
+
+
+class ShowCommand(unittest.TestCase):
+    """Tests about arguments related to the 'show' command."""
+
+    def setUp(self):
+        super().setUp()
+        self.parser_agent = cliarguments.ParserAgent(
+            app_name=bitbase.APP_NAME,
+            bin_name=bitbase.BINARY_NAME_CLI)
+
+    def test_simple(self):
+        sut = cliarguments.parse_arguments(['show'], self.parser_agent)
+        self.assertEqual(sut.command, 'show')
+        self.assertIs(sut.func, clicommands.show_backups)
+
+    def test_usage(self):
+        sut = cliarguments.parse_arguments(
+            ['show', '--usage'], self.parser_agent)
+        self.assertEqual(sut.command, 'show')
+        self.assertTrue(sut.usage)
+
+    def test_usage_last(self):
+        sut = cliarguments.parse_arguments(
+            ['show', '--usage', '--last'], self.parser_agent)
+        self.assertEqual(sut.command, 'show')
+        self.assertTrue(sut.usage)
+        self.assertTrue(sut.last)

common/test/test_backintime.py

@@ -251,3 +251,25 @@ def test_diagnostics_arg(self):
                          bitbase.APP_NAME)
         self.assertEqual(diagnostics["backintime"]["version"],
                          version.__version__)
+
+    def test_show_with_usage(self):
+        snapshot_root = '/tmp/snapshots/backintime/test-host/test-user/1'
+
+        subprocess.getoutput(f'rm -rf {snapshot_root}')
+        os.makedirs(os.path.join(snapshot_root, '20260101-010000-001', 'backup'))
+        os.makedirs(os.path.join(snapshot_root, '20260315-083000-002', 'backup'))
+
+        proc = subprocess.Popen(["./backintime",
+                                 "--config", "test/config",
+                                 "show", "--usage"],
+                                stdout=subprocess.PIPE,
+                                stderr=subprocess.PIPE)
+        output, error = proc.communicate()
+        output_str = output.decode()
+
+        self.assertEqual(proc.returncode, 0,
+                         f'show --usage failed. stderr: {error.decode()}')
+
+        self.assertIn('Total disk usage:', output_str)
+        self.assertIn('20260101-010000-001', output_str)
+        self.assertIn('20260315-083000-002', output_str)

common/version.py

@@ -13,7 +13,7 @@
 import re
 
 # Version string regularyly used by the application and presented to users.
-__version__ = '2.0.0-dev.5d7ff833'
+__version__ = '2.0.0-dev.250edd74'
 
 # Version string ends with lower case ``rc`` and optionally with a number.
 # e.g. "1.6.0rc", "1.6.0-rc", "1.6.0-rc2"