How to Gzip File Compression in Unix

Gzip is a Unix utility program to compress files. Files compressed using Gzip are replaced by a smaller file with the same name and a suffix indicating it is a Gzip file. Gzip possess a number of functional options. For example, instead of compressing to a new file, the output of Gzip may be directed to STDOUT to feed a Unix command pipe.

Difficulty: Moderate

Instructions

1. Type ls -l in a Unix shell at the command prompt to identify the file or files you wish to compress

2. Enter "gzip" and then a filename. The filename may include characters expanded by a shell such as ? or *. All selected files will be compressed individually.

3. Key in ls -l to see the result. Compare the zipped file size to the original file and you will see the effect of Gzip.

4. Use the -d option to uncompress Gzip files. To expand the file to its original size and filename use the command "gzip -d" followed by the filename.

5. Type "zcat filename > newfile" to place a compressed file into a new file.

Tips & Warnings

• Use the -r option to compress all files in the working directory and its child directories.
• Gzip provide the option to run faster with less compression or slower with greater compression in ten steps.
• Gzip is a Unix tool. Files zipped using Gzip cannot be unzipped in windows system by using popular tools like Winzip.