Linux commands for Compressing and Archiving File

1. gzip and gunzip

gzip command is used to compress the file, and gunzip is used to de-compress it.

Usage:

gzip <file name>

It provides the extension .gz and removes the original file

Example:

$ wc sample_copy.txt

      65 2776 17333 sample_copy.txt

$ gzip sample_copy.txt

$ wc sample_copy.txt.gz

      26 155 7095 sample_copy.txt.gz

The compression ratio depends on the type, size and nature of the file

Usage:

gunzip <file name with.gz>

Example:

$ gunzip sample_copy.txt.gz

$ /*do ls and you can see the original file*/

If you want to compress the directory contents recursively, use -r option with gzip command and unzip it use the same option with gunzip command.

2. tar : The archival program

tar command is used to create archive that contains a group or file or entire directory structure.

It is generally used for back ups.

Usage:

tar [options]

<file1 or dir> . . .

Options:

• -c Create an archive
• -x Extract files from archive
• -t Display files in archive
• -f arch Name the archive arch

Examples:

$ tar -cvf compression.tar compression

compression/ //v for verbose

compression/temp/

compression/temp/sample2.txt

compression/sample1.txt

• We can use tar and gzip command in succession to compress the tar file.

$ tar -cvf compression.tar compression
$ gzip compression.tar
$ //will create compression.tar.gz file

• For un-compression the file first use gunzip command, which will create a tar file and then use tar command to untar the contents

$ gunzip compression.tar.gz
$ tar -xvf compression.tar

• To just view the contents of the tar file use -t option 

$ tar -tvf compression.tar

• Instead of doing tar first and then gzip next, we can combine both of them using the option -z

$ tar -cvzf compression.tar.gz compression
compression/
compression/temp/
compression/temp/sample2.txt
compression/sample1.txt

•  We can de-compress .tar.gz agin in a single command using the option -z with -x

$ tar -xvzf compression.tar.gz

 3. zip and unzip: compressing and archiving

zip command can be used for archiving as well as compressing the contents of the directory or the file.

Usage:

zip [options] output.zip <files to be zipped or directory>

Example:

$ zip sample1.zip sample1.txt

//will create sample1.zip file

• Use -r option to recursively zip the contents of the directory

$ zip -r compression.zip compression
// will create compression.zip file

• To un-compress the file use unzip command 

$ unzip compression.zip
// will uncompress the compression.zip file