Merge pull request #9083 from ThomasWaldmann/fix-7144-master

docs: improve borg help patterns (port of #9054 to master)

src/borg/archiver/help_cmd.py

@@ -21,21 +21,27 @@ class HelpMixIn:
         - in the file given with ``--patterns-from`` option and
         - for ``PATH`` arguments that explicitly support them.
 
-        Borg always stores all file paths normalized and relative to the
-        current recursion root. The recursion root is also named ``PATH`` in
-        Borg commands like `borg create` that do a file discovery, so do not
-        confuse the root with the ``PATH`` argument of e.g. `borg extract`.
+        The path/filenames used as input for the pattern matching start with the
+        currently active recursion root. You usually give the recursion root(s)
+        when invoking borg and these can be either relative or absolute paths.
 
-        Starting with Borg 1.2, paths that are matched against patterns always
-        appear relative. If you give ``/absolute/`` as root, the paths going
-        into the matcher will start with ``absolute/``.
-        If you give ``../../relative`` as root, the paths will be normalized
-        as ``relative/``.
+        Be careful, your patterns must match the archived paths:
+
+        - Archived paths never start with a leading slash ('/'), nor with '.', nor with '..'.
+
+          - When you back up absolute paths like ``/home/user``, the archived
+            paths start with ``home/user``.
+          - When you back up relative paths like ``./src``, the archived paths
+            start with ``src``.
+          - When you back up relative paths like ``../../src``, the archived paths
+            start with ``src``.
 
         Borg supports different pattern styles. To define a non-default
         style for a specific pattern, prefix it with two characters followed
         by a colon ':' (i.e. ``fm:path/*``, ``sh:path/**``).
 
+        The default pattern style for ``--exclude`` differs from ``--pattern``, see below.
+
         `Fnmatch <https://docs.python.org/3/library/fnmatch.html>`_, selector ``fm:``
             This is the default style for ``--exclude`` and ``--exclude-from``.
             These patterns use a variant of shell pattern syntax, with '\\*' matching
@@ -122,6 +128,17 @@ class HelpMixIn:
 
         Examples::
 
+            # Exclude a directory anywhere in the tree named ``steamapps/common``
+            # (and everything below it), regardless of where it appears:
+            $ borg create -e 'sh:**/steamapps/common/**' archive /
+
+            # Exclude the contents of ``/home/user/.cache``:
+            $ borg create -e 'sh:home/user/.cache/**' archive /home/user
+            $ borg create -e home/user/.cache/ archive /home/user
+
+            # The file '/home/user/.cache/important' is *not* backed up:
+            $ borg create -e home/user/.cache/ archive / /home/user/.cache/important
+
             # Exclude '/home/user/file.o' but not '/home/user/file.odt':
             $ borg create -e '*.o' archive /
 
@@ -129,11 +146,6 @@ class HelpMixIn:
             # not '/home/user/importantjunk' or '/etc/junk':
             $ borg create -e 'home/*/junk' archive /
 
-            # Exclude the contents of '/home/user/cache' but not the directory itself:
-            $ borg create -e home/user/cache/ archive /
-
-            # The file '/home/user/cache/important' is *not* backed up:
-            $ borg create -e home/user/cache/ archive / /home/user/cache/important
 
             # The contents of directories in '/home' are not backed up when their name
             # ends in '.tmp'