Programming with awk

Built-in variables

``awk built-in variables'' lists the built-in variables that awk maintains. You have already learned some of these; others appear in this and later sections.

awk built-in variables

Variable Meaning Default

ARGC number of command-line arguments -

ARGV array of command-line arguments -

FILENAME name of current input file -

FNR record number in current file -

FS input field separator blank&tab

NF number of fields in current record -

NR number of records read so far -

OFMT output format for numbers %.6g

OFS output field separator blank

ORS output record separator newline

RS input record separator newline

RSTART index of first character matched by match -

RLENGTH length of string matched by match -

SUBSEP subscript separator "\034"

Variable	Meaning	Default
`ARGC`	number of command-line arguments	-
`ARGV`	array of command-line arguments	-
`FILENAME`	name of current input file	-
`FNR`	record number in current file	-
`FS`	input field separator	blank&tab
`NF`	number of fields in current record	-
`NR`	number of records read so far	-
`OFMT`	output format for numbers	%.6g
`OFS`	output field separator	blank
`ORS`	output record separator	newline
`RS`	input record separator	newline
`RSTART`	index of first character matched by match	-
`RLENGTH`	length of string matched by match	-
`SUBSEP`	subscript separator	"\034"