Explanation: The tar command is used to create or extract compressed archive files that contain multiple files or directories. The tar command has the following syntax: tar [options] [archive-file] [file or directory…]. The options argument specifies how the tar command should operate and what kind of compression should be used. The archive-file argument is the name of the archive file to be created or extracted. The file or directory argument is the name of one or more files or directories to be included in or extracted from the archive file.
The following are some of the common options for the tar command:
- -c: create a new archive file.
- -x: extract files from an existing archive file.
- -t: list the contents of an archive file.
- -v: show the progress of the operation.
- -f: specify the name of the archive file.
- -z: use gzip compression or decompression.
- -j: use bzip2 compression or decompression.
- -J: use xz compression or decompression.
The options -z and -j are used to handle compression with the tar command. The option -z uses the gzip program to compress or decompress the archive file, which usually has the extension .tar.gz or .tgz. The option -j uses the bzip2 program to compress or decompress the archive file, which usually has the extension .tar.bz2 or .tbz. Both gzip and bzip2 are popular compression programs that reduce the size of files by removing redundant or unnecessary information.
For example, to create a compressed archive file called backup.tar.gz that contains the files and directories in the current directory, the following command can be used:
tar -czvf backup.tar.gz .
To extract the files and directories from the archive file backup.tar.gz to the current directory, the following command can be used:
tar -xzvf backup.tar.gz
To create a compressed archive file called backup.tar.bz2 that contains the files and directories in the current directory, the following command can be used:
tar -cjvf backup.tar.bz2 .
To extract the files and directories from the archive file backup.tar.bz2 to the current directory, the following command can be used:
tar -xjvf backup.tar.bz2
The other options in the question are not related to compression. The option -bz is invalid, as there is no such option for the tar command. The option -g is used to create or update an incremental archive file, which only contains the files that have changed since the last backup. The option -z2 is also invalid, as there is no such option for the tar command. References:
- Linux Essentials Version 1.6 Objectives: 3.1. Archiving Files on the Command Line1
- Linux Essentials Version 1.6 Exam Study Resources: Linux Essentials Manual - Chapter 9. The Power of the Command Line - 9.1. Archiving Files on the Command Line - 9.1.1. The tar Command2
- Linux Essentials Version 1.6 Exam Study Resources: Linux Essentials Manual - Appendix A. Answers to the Exercises - Chapter 9. The Power of the Command Line - 9.1. Archiving Files on the Command Line - Exercise 9.1.12
