How to sum the third column?
e.g., calculate total tps across all physical disks from iostat -d output:Device: tps Blk_read/s Blk_wrtn/s Blk_read Blk_wrtn
sda 3.73 30.38 67.80 4864950 10857636
sdb 3.82 30.39 71.74 4866793 11488576
sdc 0.00 0.05 0.00 7208 8
iostat -d |egrep "sd.\ " | awk 'BEGIN {x=0} {x+=$2} END {print x}'
or, less elegantly,
iostat -d| egrep "sd.\ " | awk 'BEGIN {ORS=""}; {print $2"+"}' | ( cat; echo 0)|bc
How to grab just certain columns?
How do I use awk to print the first column, and then the third through the end, for example to grab just the fields I want from an apache log file?awk '{ print $1" " substr($0, index($0,$6)) }' /var/log/httpd/access_log*
gives us something like
10.95.10.20 "POST /license/associateproduct.php HTTP/1.1" 200 8 "-" "Java/1.6.0_17"
10.95.14.248 "POST /license/authorize.php HTTP/1.1" 200 84 "-" "PycURL/7.19.5"
