1 @c This is part of the GNU tar manual.
2 @c Copyright (C) 2017-2019 Free Software Foundation, Inc.
3 @c This file is distributed under GFDL 1.3 or any later version
4 @c published by the Free Software Foundation.
6 This appendix provides several recipes for performing common tasks
10 * copy directory hierarchy::
11 * intermediate directories::
14 @node copy directory hierarchy
15 @appendixsec Copying directory hierarchies
17 This is a traditional way to copy a directory hierarchy preserving
18 the dates, modes, owners and link-structure of all the files therein.
19 It was used back when the @command{cp} command lacked the @option{-a}
23 $ @kbd{(cd sourcedir; tar -cf - .) | (cd targetdir; tar -xf -)}
27 You can avoid subshells by using @option{-C} option:
30 $ @kbd{tar -C sourcedir -cf - . | tar -C targetdir -xf -}
34 The same command using long option forms:
38 $ @kbd{(cd sourcedir; tar --create --file=- . ) \
39 | (cd targetdir; tar --extract --file=-)}
48 $ @kbd{tar --directory sourcedir --create --file=- . \
49 | tar --directory targetdir --extract --file=-}
53 @node intermediate directories
54 @appendixsec Restoring Intermediate Directories
56 A common concern is how to extract permissions and ownerships of
57 intermediate directories when extracting only selected members from
58 the archive. To illustrate this, consider the following archive:
63 drwxr-xr-x root/root 0 2017-11-16 14:39 foo/
64 dr-xr-x--- gray/user 0 2017-11-16 14:39 foo/bar/
65 -rw-r--r-- gray/user 10 2017-11-16 14:40 foo/bar/file
69 Suppose you extract only the file @file{foo/bar/file}, while being
73 # @kbd{tar xvf A.tar foo/bar/file}
77 Now, let's inspect the content of the created directories:
82 427257 0 drwxr-xr-x 3 root root 16 Nov 17 16:10 foo
83 427258 0 drwxr-xr-x 2 root root 17 Nov 17 16:10 foo/bar
84 427259 0 -rw-r--r-- 1 gray user 10 Nov 6 14:40 foo/bar/file
88 The requested file is restored, including its ownership and
89 permissions. The intermediate directories, however, are created with
90 the default permissions, current timestamp and owned by the current
91 user. This is because by the time @command{tar} has reached the requested file,
92 it had already skipped the entries for its parent directories, so it
93 has no iformation about their ownership and modes.
95 To restore meta information about the intermediate directories,
96 you'll need to specify them explicitly in the command line and use the
97 @option{--no-recursive} option (@pxref{recurse}) to avoid extracting
100 To automate this process, @cite{Neal P. Murphy} proposed the following
101 shell script@footnote{The original version of the script can be
102 seen at @uref{http://lists.gnu.org/archive/html/bug-tar/2016-11/msg00024.html}}:
110 while [ -n "$path" -a "$path" != "." ]
115 done < $2 | sort | uniq) |
116 tar -x --no-recursion -v -f $1 -T - -T $2
120 The script takes two arguments: the name of the archive file, and the
121 name of the file list file.
123 To complete our example, the file list will contain single line:
129 Supposing its name is @file{file.list} and the script is named
130 @file{restore.sh}, you can invoke it as follows:
133 # @kbd{sh restore.sh A.tar file.list}