awk
if we want to exreact and print line 1 and 3 separeted by comma from file a.txt
$ awk -F":" '{ print $1 $3 }' a.txt
$1 == "fred" { print $3 }
$5 ~ /root/ { print $3 }
{
if ( $5 ~ /root/ )
{
print $3
}
}
Number of fields
NF == 3 { print "this particular record has three fields: " $0 }
Record number
(NR < 10 ) || (NR > 100) { print "We are on record number 1-9 or 101+" }
{
#skip header
if ( NR > 10 )
{
print "ok, now for the real information!"
}
}
extract MAC address using ifconfig
ifconfig |grep -n 'HWaddr' | awk '{ print $5}'
SNR. for WIFI
iwconfig | grep -n 'Tx-Power' | awk '{ print $5}'|cut -c 10-
get PID
ps -e| grep 'name_of_process'| awk '{print $1 $4}'
get ip
ifconfig | grep 'inet addr:192'|awk '{ print $2}'|cut -c 6-
sed
s: substitution
fibonacci series
awk 'BEGIN {a=1;b=1; while(++x<=1000){print a; t=a;a=a+b;b=t}; exit}'