Would any body explain me pieces in following awk ?

[netbackup1234]

Hi
I got following from somebody and trying to understand..
awk 'NR==FNR{a[$0];next}{if ($0 in a) {print $0}}' cbdnode1 cbdnode2

specialy NR==FNR{a[$0];next}

Thank you

 

[PHV]

NR==FNR{a[$0];next}
Populate the a array while reading the first file.

Hope This Helps, PH.
Want to get great answers to your Tek-Tips questions? Have a look at FAQ219-2884 or FAQ181-2886

 

[Annihilannic]

NR is the record number currently being processed overall.

FNR is the record number currently being processed within the current file.

So they will only be equal while it is processing the first input file.

Annihilannic.

 

[netbackup1234]

Thank you Annililannic
I see this( 'NR==FNR{a[$0];next}) part of awk handles cbdnode1 file and other part ( {if ($0 in a) {print $0}}') handles cbdnode2 file.
By the way what happens if there are more than 2 input files to process ?

 

[Annihilannic]

The first part would be use handle the first file, and the second part would handle all of the rest of the input files.

Annihilannic.