Linux in a Nutshell, Fifth Edition

Gawk-specific Features | 777

gawk

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constants with a leading 0x or 0X. The hexadecimal digits a–f may be in either

uppercase or lowercase.

$ gawk 'BEGIN { print 042, 42, 0x42 }'

34 42 66

Use the strtonum( ) function to convert octal or hexadecimal input data into

numerical values.

User-Defined Functions

gawk allows you to define your own functions. This makes it easy to encapsulate

sequences of steps that need to be repeated into a single place and reuse the code

from anywhere in your program.

The following function capitalizes each word in a string. It has one parameter,

named input, and five local variables, which are written as extra parameters:

# capitalize each word in a string

function capitalize(input, result, words, n, i, w)

{

result = ""

n = split(input, words, " ")

for (i = 1; i <= n; i++) {

w = words[i]

w = toupper(substr(w, 1, 1)) substr(w, 2)

if (i > 1)

result = result " "

result = result w

}

return result

}

# main program, for testing

{ print capitalize($0) }

With this input data:

A test line with words and numbers like 12 on it.

This program produces:

A Test Line With Words And Numbers Like 12 On It.

For user-defined functions, no space is allowed between the func-

tion name and the left parenthesis when the function is called.

Gawk-specific Features

This section describes features unique ...