How do you archive and compress files in Linux using "tar" command?

1 What is a tar archive?

A tar archive is a single file that contains one or more files or directories, optionally compressed with a compression algorithm. Tar archives have the .tar extension, or a combination of .tar and another extension that indicates the compression method, such as .tar.gz for gzip or .tar.bz2 for bzip2. Tar archives preserve the file permissions, ownership, and timestamps of the original files.

2 How to create a tar archive?

To create a tar archive, you need to use the tar command with the -c option, followed by the name of the archive file and the files or directories you want to include. For example, to create a tar archive named backup.tar that contains the files file1.txt and file2.txt, you would run: tar -c -f backup.tar file1.txt file2.txt If you want to compress the archive with gzip, you can add the -z option, or use the .tar.gz extension: tar -c -z -f backup.tar.gz file1.txt file2.txt You can also use other compression methods, such as -j for bzip2 or -J for xz, by changing the option and the extension accordingly.

3 How to extract a tar archive?

To extract a tar archive, you need to use the tar command with the -x option, followed by the name of the archive file and optionally the files or directories you want to extract. For example, to extract all the files from backup.tar.gz, you would run: tar -x -z -f backup.tar.gz If you only want to extract file1.txt, you can specify it after the archive name: tar -x -z -f backup.tar.gz file1.txt You can also use the -C option to specify the destination directory for the extracted files, instead of the current directory.

6 How to use tar options and filters?

The tar command has many other options and filters that you can use to customize your archiving and compression tasks. Some of the most useful ones are:

- -a: This option lets tar detect the compression method based on the archive extension, so you don't have to specify it manually.

- -r: This option lets you append files to an existing archive, instead of creating a new one.

- -k: This option prevents tar from overwriting existing files when extracting an archive.

- --exclude: This option lets you exclude files or directories that match a pattern from the archive.

- --strip-components: This option lets you remove a specified number of leading path components from the files when extracting an archive.

You can also use filters to apply commands or transformations to the files before or after archiving or extracting them. For example, you can use the --to-command filter to send the extracted files to a command, such as cat or md5sum, instead of writing them to disk. You can also use the --xform filter to modify the file names in the archive with a sed expression.

For more information and examples on how to use tar options and filters, you can check the man page or the online documentation of tar.

7 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?