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You're reading from  Linux Command Line and Shell Scripting Bible - Third Edition

Product typeBook
Published inJan 2015
PublisherWiley
ISBN-139781118983843
Edition3rd Edition
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Authors (2):
Richard Blum
Richard Blum
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Richard Blum

Richard Blum has more than 25 years as a network and systems administrator, currently managing Microsoft, Unix, Linux, and Novell servers for a network with more than 3,500 users. He has developed online programming and Linux courses that he teaches to students worldwide.
Read more about Richard Blum

Christine Bresnahan
Christine Bresnahan
author image
Christine Bresnahan

Christine Bresnahan has worked in the IT industry for more than 30 years and is currently an adjunct professor of Python programming and Linux system administration classes at Ivy Tech Community College in Indianapolis. She is the co-author of Linux Bible, Eighth Edition, and Linux Command Line and Shell Scripting Bible.
Read more about Christine Bresnahan

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Structured Commands

The gawk programming language supports the usual cast of structured programming commands. This section describes each of these commands and demonstrates how to use them within a gawk programming environment.

The if statement

The gawk programming language supports the standard if-then-else format of the if statement. You must define a condition for the if statement to evaluate, enclosed in parentheses. If the condition evaluates to a TRUE condition, the statement immediately following the if statement is executed. If the condition evaluates to a FALSE condition, the statement is skipped. You can use this format:

if (condition)
   statement1

Or you can place it on one line, like this:

if (condition) statement1

Here's a simple example demonstrating this format:

$ cat data4
10
5
13
50
34
$ gawk '{if ($1 > 20) print $1}' data4
50
34
$

Not too complicated. If you need to execute multiple statements in the if statement, you must enclose them with braces...

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Linux Command Line and Shell Scripting Bible - Third Edition
Published in: Jan 2015Publisher: WileyISBN-13: 9781118983843

Authors (2)

author image
Richard Blum

Richard Blum has more than 25 years as a network and systems administrator, currently managing Microsoft, Unix, Linux, and Novell servers for a network with more than 3,500 users. He has developed online programming and Linux courses that he teaches to students worldwide.
Read more about Richard Blum

author image
Christine Bresnahan

Christine Bresnahan has worked in the IT industry for more than 30 years and is currently an adjunct professor of Python programming and Linux system administration classes at Ivy Tech Community College in Indianapolis. She is the co-author of Linux Bible, Eighth Edition, and Linux Command Line and Shell Scripting Bible.
Read more about Christine Bresnahan