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Linux Shell Scripting Essentials
book

Linux Shell Scripting Essentials

by Sinny Kumari
November 2015
Beginner content levelBeginner
282 pages
5h 5m
English
Packt Publishing
Content preview from Linux Shell Scripting Essentials

Testing expressions with a test

The shell builtin command test can be used to check file types and compare expressions value. The syntax is test EXPRESSION or the test command is also equivalent to [ EXPRESSION ].

It returns the exit code 1 (false) if the EXPRESSION result is 0, and 0 (true) for a non-zero EXPRESSION result.

If no EXPRESSION is provided, the exit status is set to 1 (false).

File checks

Different kinds of checks can be done on the file using the test command; for example, file existence test, directory test, regular file check, symbolic link check, and so on.

The options available to do various checks on a file are explained in the following table:

Option

Description

-e

fileChecks whether the file exists

-f file

The file is a regular ...

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Publisher Resources

ISBN: 9781785284441Supplemental Content