Backup Command ‘tar’
Tar Command in Unix with Examples
The archive format preserves the directory structure, and the file system attributes such as permissions and dates.
Tar Syntax:
tar [function] [options] [paths]
Tar options:
The tar command supports the following functions:
- tar -c: Create a new archive.
- tar -A: Append a tar file to another archive.
- tar -r: Append a file to an archive.
- tar -u: Update files in an archive if the one in the filesystem is newer.
- tar -d: Find the diff between an archive and the filesystem.
- tar -t: List the contents of an archive.
- tar -x: Extract the contents of an archive.
While specifying the function, the ‘-‘ prefix is not required, and the function can be followed by other single letter options.
Some of the supported options include:
- -j: Read or write archives using the bzip2 compression algorithm.
- -J: Read or write archives using the xz compression algorithm.
- -z: Read or write archives using the gzip compression algorithm.
- -a: Read or write archives using the compression algorithm determined by the archive file name.
- -v: Perform the operations verbosely.
- -f: Specify the file name for the archive.
Examples:
Create an archive file containing file1 and file2
$ tar cvf archive.tar file1 file2
Create an archive file containing the directory tree below dir
$ tar cvf archive.tar dir
List the contents of archive.tar
$ tar tvf archive.tar
Extract the contents of archive.tar to the current directory
$ tar xvf archive.tar
Create an archive file containing the directory tree below dir and compress it using gzip
$ tar czvf archive.tar.gz dir
Extract the contents of the gzipped archive file
$ tar xzvf archive.tar.gz
Extract only the given folder from the archive file
$ tar xvf archive.tar docs/work
Extract all “.doc” files from the archive
$ tar xvf archive.tar –-wildcards ‘*.doc’
Conclusion
The archive format of Tar Command in Unix preserves the directory structure, and the file system attributes such as permissions and dates.