tar Command
Archives and compressed files are used for many different purposes in the Linux world. In this article, we will review the tar command examples. Using tar; we will create "tarballs" with "gzip", "bzip2" and "xz".
tar Command Examples
As stated in the manual page; "GNU tar" saves many files together in a single tape or disk archive and can restore individual files from the archive. tar stands for "Tape Archive". You can get tar.gz extension files by compressing a tar file. Such compressed archive files are known as "tarball".
Creating an Archive with the Tar Command
Let's create some files first. Let's create a text file with I/O redirection and a data file with the dd command:
[root@gnuadmin ~]# cat /var/log/lastlog > last.log
[root@gnuadmin ~]# journalctl > system_logs
[root@gnuadmin ~]# dd if=/dev/urandom of=data_file bs=1M count=100
100+0 records in
100+0 records out
104857600 bytes (105 MB) copied, 3,47781 s, 30,2 MB/s
[root@gnuadmin ~]# ls -lh
total 101M
-rw-r--r--. 1 root root 100M Jan 13 22:55 data_file
-rw-r--r--. 1 root root 286K Jan 13 22:52 last.log
-rw-r--r--. 1 root root 70K Jan 13 22:51 system_logs
Now let's add these files to a "tar archive":
[root@gnuadmin ~]# tar -cf my_archive.tar last.log data_file system_logs
[root@gnuadmin ~]# tar -cvf my_verbose.tar last.log data_file system_logs
last.log
data_file
system_logs
The "-c" option of the tar command stands for "create". "-f" allows you to specify the name of the archive you will create. The arguments in the continuation of the command specify the files to be added to the archive. If you want to see the processed files one by one during the creation of the archive, you can "verbose" with "-v".
Listing Files in the Tar Archive
With the tar -tvf command you can list the files in the tar archive:
[root@gnuadmin ~]# tar -tvf my_archive.tar
-rw-r--r-- root/root 292000 2022-01-13 22:52 last.log
-rw-r--r-- root/root 104857600 2022-01-13 22:55 data_file
-rw-r--r-- root/root 70933 2022-01-13 22:51 system_logs
Extracting Files from a tar Archive
With the tar -xf command you can extract the files in the tar archive:
[root@gnuadmin ~]# ls -l
total 205520
-rw-r--r--. 1 root root 105226240 Jan 13 22:58 my_archive.tar
-rw-r--r--. 1 root root 105226240 Jan 13 22:58 my_verbose.tar
[root@gnuadmin ~]# tar -xf my_archive.tar
[root@gnuadmin ~]# ls -l
total 308280
-rw-r--r--. 1 root root 104857600 Jan 13 22:55 data_file
-rw-r--r--. 1 root root 292000 Jan 13 22:52 last.log
-rw-r--r--. 1 root root 105226240 Jan 13 22:58 my_archive.tar
-rw-r--r--. 1 root root 105226240 Jan 13 22:58 my_verbose.tar
-rw-r--r--. 1 root root 70933 Jan 13 22:51 system_logs
Creating a tarball
You can create "tarball" by compressing your tar archives.
With the gzip Algorithm
If you want to use the "gzip" algorithm for compression, you can use the "-z" option:
With the bzip2 Algorithm
If you want to use the "bzip2" algorithm for compression, you can use the "-j" option:
Note: If you get "tar (child): bzip2: Cannot exec: No such file or directory" error, you need to install "bzip2" package on your system.
With the xz Algorithm
If you want to use the "xz" algorithm for compression, you can use the "-J" option: