Linux in a Nutshell, Fifth Edition

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Chapter 11: The gawk Programming Language

This is the Title of the Book, eMatter Edition

Copyright © 2006 O’Reilly & Associates, Inc. All rights reserved.

function

function name(parameter-list) {

statements

}

Create name as a user-defined function consisting of awk state-

ments that apply to the specified list of parameters. No space is

allowed between name and the left parenthesis when the function

is called.

gensub

gensub(regex, str, how [, target]) {G}

General substitution function. Substitute str for matches of the

regular expression regex in the string target.Ifhow is a number,

replace the howth match. If it is "g" or "G", substitute globally. If

target is not supplied, $0 is used. Return the new string value. The

original target is not modified. (Compare with gsub and sub.) Use

& in the replacement string to stand for the text matched by the

pattern.

getline

getline

getline [var] [< file]

command | getline [var]

command |& getline [var] {G}

Read next line of input.

The second form reads input from file, and the third form reads the

output of command. All forms read one record at a time, and each

time the statement is executed, it gets the next record of input. The

record is assigned to $0 and is parsed into fields, setting NF, NR

and FNR. If var is specified, the result is assigned to var and $0 and

NF are not changed. Thus, if the result is assigned to a variable, the

current record does not change. ...