awk: The Linux Text Processing Tool Explained

Published 2026-08-05 · Learn Linux

The awk command splits each line of input into fields and lets you print or calculate with them. Its most common use is pulling out a column: awk '{print $1}' file prints the first word of every line. awk is the tool to reach for whenever a line of text has columns.

Print a column

Fields are numbered from 1: $1 is the first, $2 the second, and $0 is the whole line. The default separator is any run of spaces or tabs.

$ awk '{print $1}' names.txt

$ awk '{print $1, $3}' scores.txt

Change the field separator with -F

For comma- or colon-separated data, tell awk the separator with -F. Parsing /etc/passwd is the classic example.

$ awk -F: '{print $1}' /etc/passwd

Filter lines with a condition

Place a condition before the action. This prints the third field for every line whose second field is greater than 10.

$ awk '$2 > 10 {print $3}' data.txt

Count lines and sum numbers

awk does arithmetic as it reads. END runs after the last line, so you can total a column. This sums every line of a file:

$ awk '{sum += $2} END {print sum}' amounts.txt

Use awk with pipes

awk shines on command output. The classic combo with ps prints just the PID and command columns. For more text editing, see sed.

$ ps aux | awk '{print $2, $11}'

The awk reference page covers the full language.