Gzip and Tar

Gzip:

1. Gzip is used to compress a file. To zip "thisfile", type gzip thisfile. You'll get a file named thisfile.gz.
2. $gzip thisfile
3. $thisfile.gz
4. To unzip thisfile.gz, type gunzip thisfile.gz.
5. $gunzip thisfile.gz
6. Gzip supports 9 levels of compression; 1 being the fastest and least compressed; 9 being the slowest and most compressed; 6 being the default. To get the best compression, use the command: gzip -9 readme

Tar:

1. Tar is used to pack the entire contents of a directory or directories into a single file called a tarball.
2. Tar preserves the entire directory organization including file ownership, permissions, links, and the directory structure.
3. The most commonly used tar functions are:

• c - create an archive
• x - extract files from an archive
• t - list the contents of an archive

• v - verbose
• f filename - use the specified file
• z - gzip/gunzip

Examples: Back |up the contents of the home directory for gemini (/home/gemini) in a tarball called a.tar on a floppy disk.

1. 
   mount /floppy
   cd /home
   tar -cvf /floppy/a.tar gemini
   
   Explanation:
   • Change to the parent of the /home/gemini directory.
   • Create a backup of gemini in the file /floppy/a.tar.
     
2. Now, check the contents of the tarball that you just created.
   
   cd /floppy
   tar -tvf a.tar
   
3. Back |up the contents of the etc directory in an archive called etc.tar . Make sure that the archive is created in your own home directory.
   
   cd /
   tar -cvf ~/etc.tar etc
   
   Explanation:
   • Change to the parent of the /etc directory.
   • Create a backup of etc in the file ~/etc.tar
     
4. Back |up and compress the contents of the home directory into the tarball home.tgz on a floppy disk.
   
   mount /floppy
   cd /
   tar -cvzf /floppy/home.tgz home
   
   Explanation:
   • change to the parent of the /home directory
   • Create a compressed backup of home in the file /floppy/home.tgz.
     
5. Now check the contents of the archive that you just created.
   
   cd /floppy
   tar -tvzf home.tgz
   
6. Unpack the archive home.tgz on your floppy.
   
   cd /floppy
   tar -xvzf home.tgz
   
   Explanation:
   • change to the /floppy directory
   • unpack and unzip the tarball home.tgz