(tar)Extracting Files bis

Extracting Files from an Archive ter

How to Extract Members from an Archive

How to Extract Members from an Archive

Extract Files from an Archive into Your Current Directory
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   Obviously, the ultimate goal of `tar' users is to eventually get
their files back.  To do this, use the `--extract' (`-x') or `--get'
operation.  `--extract' (`-x') can be used to retrieve individual files
from an archive, or can be used to write all the files in the archive
back into the file system.

   In the previous example you concatenated two archives, `music', and
`practice/records'.  To now retrieve the complete contents of `music'
(the target file in the concatenation process), you would, from the
home directory:

   * Invoke `tar' and specify the operation to extract files from an
     archive (`--extract' (`-x') or `--get'.

   * Specify the name of the archive the files will be extracted
     from--`--file=ARCHIVE-NAME' (`-f ARCHIVE-NAME').

   * Specify the names of the files you wish to extract, as file name
     arguments (in this case you want to extract the entire archive, so
     you don't need to specify anything).

     % tar --extract --file=music
     tar: Could not make directory practice : File exists

Because the files stored originally in `music' were stored as files in
a subdirectory (not as files in the working directory), they are stored
in the archive with a leading directory name--`tar', in restoring them,
has tried to recreate that directory and failed: the directory already
exists.  The extraction has not been aborted, however.  If you now
change into the `practice' directory and generate a directory listing,
you will find that `jazz', which we removed in an earlier example, has
been resurrected.

     % cd practice
     % ls
     blues	   classical  folk	 jazz	    records    rock

   If you look more closely at the files in the directory, however, you
will find that `blues' and `folk' are, in fact, the original versions
of the file, which were stored in `music' at the beginning of the
tutorial.  `tar', in extracting the original files from `music', has
overwritten the existing files in the file system.

   While the newer versions of the files were stored in `records'
above, they can no longer be extracted from it.  `records' too was
archived by `tar' when the `practice' directory was stored in the
archive file `music', and was restored to its older incarnation when
the files in `practice' were overwritten.  However, the newer version
of `records' was concatenated with `music'.  The contents of the newer
version of `records', therefore, should have been extracted when all
the contents of `music' were extracted.  They were.  `tar' has restored
them into the working directory using the names with which they were
originally stored.  Because they were originally stored as part of
`records', in the `practice' directory, they had no preceeding
directory stored as part of their file names.  To find the latest
versions of `blues', `folk', `jazz', `rock' and `classical', look in
your home directory.

   You may wish to restore the files in your `practice' directory to
their last state before we extracted the files from `music'.  Rather
than moving the files from your home directory to the `practice'
subdirectory, you can run the same extraction procedure as above using
the `practice' subdirectory as your working directory:

     % cd practice
     % tar --extract --verbose --file=~/music
     practice/
     practice/blues
     practice/folk
     practice/jazz
     practice/records
     blues
     folk
     jazz
     blues
     rock
     blues
     classical
     %

If you now examine the files in the practice directory, you will find
that the files have been restored to their previous, newer, states.
The old versions of the files, which were stored in `music' with a
preceeding directory name, have been written into a newly created
subdirectory under the working directory (which is your `practice'
subdirectory).  The new subdirectory is also called `practice'.