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Learning AWK Programming

You're reading from  Learning AWK Programming

Product type Book
Published in Mar 2018
Publisher Packt
ISBN-13 9781788391030
Pages 416 pages
Edition 1st Edition
Languages
Author (1):
Shiwang Kalkhanda Shiwang Kalkhanda
Profile icon Shiwang Kalkhanda

Table of Contents (11) Chapters

Preface Getting Started with AWK Programming Working with Regular Expressions AWK Variables and Constants Working with Arrays in AWK Printing Output in AWK AWK Expressions AWK Control Flow Statements AWK Functions GNU's Implementation of AWK – GAWK (GNU AWK) Practical Implementation of AWK

Regular expression operators

When we use the == condition, AWK looks for an exact match. However, when we use the match operator (~), AWK looks for a partial match. Here, ~ means contains. To match a specific pattern using regular expression, ~ and !~ are used. Regular expression comparisons are performed using a matching expression built with either of these two operators. The right-hand side of the ~ or !~ operator could be a regular expression or string enclosed between forward slashes (/…/).

Match operator (~):

It is represented as a tilde (~) symbol. It matches a pattern in a specific field. Its syntax is as follows:

expression ~ /regexpr/

It matches if the string value of the expression contains a sub-string matched by regular expression regexpr.

For example, if you want to print the records containing Singh or Kapur in last name field from the employees database...

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