Question

1. gzip is a useful utility in Linux. Read the webpage below about gzip. Please tell the differences between gzip and tar.

https://www.rootusers.com/11-simple-gzip-examples/

Answer 1

GZIP vs TAR
The .tar.gz extension is a very popular one when downloading files especially in non Windows operating systems. But unlike most extensions, this is not meant to identify a single program that would be used to open this file; it points to two. Tar is a file format but is also the name of the program that produces the file. Tar is an archiver, meaning it would archive multiple files into a single file but without compression. Gzip which handles the .gz extension is the compression tool that is used to reduce the disk space used by the file.

There are advantages and disadvantages in creating a zipped tarball compared to the standard applications that does both. A zipped tarball could have dramatically reduced filesize the compression tool is not compressing the files individually but treating the whole tarball as one big file. This is even more apparent when dealing with semi compressed files like GIF and JPG files.

The disadvantage of using this format is that you would be unable to extract a single file. Since the entire archive is compressed as a whole, you would also need to uncompress the whole archive before extracting a single file. Extracting a single file from a large zipped tarball could take significantly longer compared to extracting a single file from the same files compressed and archived by a different tool like Winrar or Winzip.

Summary:
1. Gzip is a compression tool used to reduce the size of a file
2. Tar is an archiver used to to combine multiple files into one
3. Gzip and Tar are usually used in tandem to create Tarballs that are compressed significantly
4. Extracting an individual file can take a lot longer with zipped tarballs than with other formats

How to compress files using Gzip?

As a Unix admin, you can use the command “zip” and “gunzip” to compress and decompress files respectively. Here I am illustrating a simple example of the same.

Test file name is test.txt
To compress file to smaller:

# zip test.txt

After executing this command, the file size will reduce and will add the extension .gz to the file. Use the command “guzip” to decompress the file.

# gunzip test.txt.gz

How to create an archive using tar?

Create an archive using tar.

# tar -cvf archive.tar file1.txt file3.txt

Here the files file1 and file2 will combine together and formed the file archive.tar, you can use the tar command with switch -x to extract file from the archive created.

# tar -xvf archive.tar

Here we goes to the extension “.tar.gz”. Yes, there is an option in tar command to compress the files by using additional switches like “-z”, “-j” for Gzip and Bzip respectively.
Examples:
For gzip,

# tar -zcf file.tar.gz file2.txt file1.txt

For bzip,

# tar -jcf file.tar.bz file2.txt file1.txt