gawk command examples

gawk – pattern scanning and processing language

Print and sort the login names of all users:

BEGIN { FS = ":" }
{ print $1 | "sort" }

Count lines in a file:

{ nlines++ }
END { print nlines }

Precede each line by its number in the file:

{ print FNR, $0 }

Concatenate and line number (a variation on a theme):

{ print NR, $0 }

Run an external command for particular lines of data:

tail -f access_log |
awk '/myhome.html/ { system("nmap " $1 ">> logdir/myhome.html") }'