Adds a strip and strip-path option to bup save.

If the strip option is given bup uses all given filenames as base paths
and tries to stripe them from long to short.

If the strip-path option is given bup strip the given prefix from all
paths.

Signed-off-by: Zoran Zaric <zz@zoranzaric.de>

cmd/save-cmd.py

@@ -16,6 +16,8 @@
 q,quiet    don't show progress meter
 smaller=   only back up files smaller than n bytes
 bwlimit=   maximum bytes/sec to transmit to server
+strip      strips the path to every filename given
+strip-path= path-prefix to be stripped when saving
 """
 o = options.Options('bup save', optspec)
 (opt, flags, extra) = o.parse(sys.argv[1:])
@@ -36,6 +38,9 @@
 else:
     date = time.time()
 
+if opt.strip and opt.strip_path:
+    o.fatal("--strip is incompatible with --strip-path")
+
 is_reverse = os.environ.get('BUP_SERVER_REVERSE')
 if is_reverse and opt.remote:
     o.fatal("don't use -r in reverse mode; it's automatic")
@@ -195,7 +200,13 @@ def wantrecurse_during(ent):
         continue
 
     assert(dir.startswith('/'))
-    dirp = dir.split('/')
+    if opt.strip:
+        stripped_base_path = strip_base_path(dir, extra)
+        dirp = stripped_base_path.split('/')
+    elif opt.strip_path:
+        dirp = strip_path(opt.strip_path, dir).split('/')
+    else:
+        dirp = dir.split('/')
     while parts > dirp:
         _pop(force_tree = None)
     if dir != '/':

lib/bup/helpers.py

@@ -411,6 +411,39 @@ def parse_date_or_fatal(str, fatal):
     else:
         return date
 
+def strip_path(prefix, path):
+    """Strips a given prefix from a path.
+
+    First both paths are normalized.
+
+    Raises an Exception if no prefix is given.
+    """
+    if prefix == None:
+        raise Exception('no path given')
+
+    normalized_prefix = realpath(prefix)
+    print "normalized_prefix: " + normalized_prefix
+    normalized_path = realpath(path)
+    print "normalized_path: " + normalized_path
+    if normalized_path.startswith(normalized_prefix):
+        return normalized_path[len(normalized_prefix):]
+    else:
+        return path
+
+def strip_base_path(path, base_paths):
+    """Strips the base path from a given path.
+
+    Determines the base path for the given string and the strips it
+    using strip_path().
+    Iterates over all base_paths from long to short, to prevent that
+    a too short base_path is removed.
+    """
+    sorted_base_paths = sorted(base_paths, key=len, reverse=True)
+    for bp in sorted_base_paths:
+        if path.startswith(realpath(bp)):
+            return strip_path(bp, path)
+    return path
+
 
 # hashlib is only available in python 2.5 or higher, but the 'sha' module
 # produces a DeprecationWarning in python 2.6 or higher.  We want to support

lib/bup/t/thelpers.py

@@ -10,3 +10,21 @@ def test_parse_num():
     WVPASSEQ(pn('2 gb'), 2*1024*1024*1024)
     WVPASSEQ(pn('1e+9 k'), 1000000000 * 1024)
     WVPASSEQ(pn('-3e-3mb'), int(-0.003 * 1024 * 1024))
+
+@wvtest
+def test_strip_path():
+    prefix = "/var/backup/daily.0/localhost"
+    empty_prefix = ""
+    non_matching_prefix = "/home"
+    path = "/var/backup/daily.0/localhost/etc/"
+
+    WVPASSEQ(strip_path(prefix, path), '/etc')
+    WVPASSEQ(strip_path(empty_prefix, path), path)
+    WVPASSEQ(strip_path(non_matching_prefix, path), path)
+    WVEXCEPT(Exception, strip_path, None, path)
+
+@wvtest
+def test_strip_base_path():
+    path = "/var/backup/daily.0/localhost/etc/"
+    base_paths = ["/var", "/var/backup", "/var/backup/daily.0/localhost"]
+    WVPASSEQ(strip_base_path(path, base_paths), '/etc')