Linux in a Nutshell, Fifth Edition

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gawk

This is the Title of the Book, eMatter Edition

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

array membership operator in, and the pattern-matching operators

~ and !~ (e.g., if ($1 ~ /[Aa].*/)). A series of statements must be put

within braces. Another if can directly follow an else in order to

produce a chain of tests or decisions.

index

index(str, substr)

Return the position (starting at 1) of substr in str, or zero if substr is

not present in str.

int

int(x)

Return integer value of x by truncating any fractional part.

length

length([arg])

Return length of arg, or the length of $0 if no argument.

log

log(x)

Return the natural logarithm (base e) of x.

lshift

lshift(expr, count) {G}

Return the result of shifting expr left by count bits. Both expr and

count should be values that fit in a C unsigned long.

match

match(str, regex)

match(str, regex [, array]) {G}

Function that matches the pattern, specified by the regular expres-

sion regex, in the string str and returns either the position in str

where the match begins, or 0 if no occurrences are found. Sets the

values of RSTART and RLENGTH to the start and length of the

match, respectively.

If array is provided, gawk puts the text that matched the entire

regular expression in array[0], the text that matched the first

parenthesized subexpression in array[1], the second in array[2],

and so on.

mktime

mktime(timespec) {G}

Turns timespec ...