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Ubuntu Unleashed 2014 Edition: Covering 13.10 and 14.04,Ninth Edition by Paul Hudson, Andrew Hudson, Matthew Helmke

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Conditional Statements: if/else and unless

Perl offers two conditional statements, if and unless, which function opposite one another. if enables you to execute a block of code only if certain conditions are met so that you can control the flow of logic through your program. Conversely, unless performs the statements when certain conditions are not met.

The following sections explain and demonstrate how to use these conditional statements when writing scripts for Linux.

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