LINUX COMMAND ATLAS · COMMAND GUIDE

Linux awk command

Process text by fields and patterns; fields are separated by whitespace by default.

GNU Awk

Syntax

Command form

awk [OPTION]... 'PROGRAM' [FILE]...

5 options

Option	What it does
`-F FS, --field-separator=FS`	Set the input field separator.
`-v VAR=VALUE`	Assign a variable before the program runs.
`-f FILE`	Read the awk program from FILE.
`-e PROGRAM`	Add program source text.
`-i FILE`	Load an awk extension library (gawk).

3 examples

Process text by fields and patterns; fields are separated by whitespace by default.

awk '{print $1}' access.log

Print the first colon-separated field.

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

Print the first and third fields where the third exceeds 100.

awk '$3 > 100 {print $1, $3}' scores.txt

awk implementations differ; extensions such as -i are specific to GNU awk. Quote programs to protect them from the shell.