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Local file selection
-C dir
--directory dir
This option causes tar to change into the directory dir
before continuing. This option can be interspersed with the files
tar is to work on. For example,
tar -c iggy ziggy -C baz melvin
will place the files `iggy' and `ziggy' from the current directory on the tape, followed by the file `melvin' from the directory `baz'. This option is especially useful when you have several widely separated files that you want to store in the same directory in the archive.
Here, the file `melvin' is recorded in the archive under the precise name `melvin', not `baz/melvin'. Thus, the archive will contain three files that all appear to have come from the same directory; if the archive is extracted with plain `tar -x', all three files will be created in the current directory.
Contrast this with the command:
tar -c iggy ziggy bar/melvin
which records the third file in the archive under the name `bar/melvin' so that, if plain `tar -x' is used, the third file will be created in a subdirectory named `bar'.
Suppose that, without changing your current directory, you want
to call tar to dump files from `/users/ctd/dipp' say.
Then `--directory=directory' (`-C directory') is for you. You could do things like:
tar cfC archive.tar /users/ctd/dipp .
(the `.' means the current directory, once the `--directory=directory' (`-C directory') obeyed).
Some people might want some option to extract everything from an
archive in the current directory, ignore directory structure in
the archive. This is so rarely proper that I doubt such an option
would be really useful. It would only help getting around improper
tar usage, it might even encourage improper usage. In general,
`--directory=directory' (`-C directory') might be used to produce archives with a cleaner
structure in the first place.
-T filename
--files-from=filename
Instead of taking the list of files to work on from the command line, the list of files to work on is read from the file filename. If filename is given as `-', the list is read from standard input. Note that using both `-T -' and `-f -' will not work unless you are using the `--create' (`-c') command.
This is typically useful when you have generated the list of files to
archive with find.
--null
xargs and cpio,
and is useful with the `-print0' predicate of GNU find.
In tar, `--null' also causes `--directory=directory' (`-C directory') options to
be treated as file names to archive, in case there are any files out
there called `-C'.
--exclude=file
-X file
--exclude-from=file
This option causes tar to read a list of regular expressions (in
shell wildcard syntax), one per line, from file; tar will
ignore files matching those regular expressions. Thus if tar is
called as `tar -c -X foo .' and the file `foo' contains
a single line `*.o', no files whose names end in `.o' will be
added to the archive. Multiple `--exclude=pattern' options may be given.
-P
--absolute-names
By default, GNU tar drops a leading `/' on input or output.
This option turns off this behavior; it's equivalent to changing to the
root directory before running tar (except it also turns off the
usual warning message).
-l
--one-file-system
This option causes tar to not cross filesystem boundaries when
archiving parts of a directory tree. This option only affects files
that are archived because they are in a directory that is archived;
files named on the command line are archived regardless, and they
can be from various file systems.
This option is useful for making full or incremental archival backups
of a filesystem, as with the Unix dump command.
Files skipped due to this option are mentioned on standard error.
-K name
--starting-file=name
The `--starting-file=name' (`-K name') option causes tar to begin
extracting or listing the archive with the file filename, and
to consider only the files starting at that point in the archive.
This is useful if a previous attempt to extract files failed when
it reached filename due to lack of free space. (Assuming, of
course, that there is now free space, or that you are now extracting
into a different file system.)
-N date
--newer=date
--after-date=date
This option causes tar to only work on files whose modification
or inode-changed times are newer than the date given. The main
use is for creating an archive; then only new files are written.
If extracting, only newer files are extracted.
Remember that the entire date argument must be quoted if it contains any spaces.
The date is parsed using getdate.
Changing the Names of Members when Archiving
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