Next: Extracting Files that are Directories, Previous: Extracting an Entire Archive, Up: How to Extract Members from an Archive [Contents][Index]
To extract specific archive members, give their exact member names as arguments, as printed by --list (-t). If you had mistakenly deleted one of the files you had placed in the archive collection.tar earlier (say, blues), you can extract it from the archive without changing the archive’s structure. Its contents will be identical to the original file blues that you deleted.
First, make sure you are in the practice directory, and list the files in the directory. Now, delete the file, ‘blues’, and list the files in the directory again.
You can now extract the member blues from the archive file collection.tar like this:
$ tar --extract --file=collection.tar blues
If you list the files in the directory again, you will see that the file
blues has been restored, with its original permissions, data
modification times, and owner.1 (These parameters will be identical to those which
the file had when you originally placed it in the archive; any changes
you may have made before deleting the file from the file system,
however, will not have been made to the archive member.) The
archive file, ‘collection.tar’, is the same as it was before you
extracted ‘blues’. You can confirm this by running tar
with
--list (-t).
Remember that as with other operations, specifying the exact member name is important (See Commands That Will Fail, for more examples).
You can extract a file to standard output by combining the above options with the --to-stdout (-O) option (see Writing to Standard Output).
If you give the --verbose option, then --extract will print the names of the archive members as it extracts them.
This is only accidentally
true, but not in general. Whereas modification times are always
restored, in most cases, one has to be root for restoring the owner,
and use a special option for restoring permissions. Here, it just
happens that the restoring user is also the owner of the archived
members, and that the current umask
is compatible with original
permissions.
Next: Extracting Files that are Directories, Previous: Extracting an Entire Archive, Up: How to Extract Members from an Archive [Contents][Index]