nawk question - addition of a column
 

Hi,

I have a file, like the following, where I would like to addition up column 5 (length).

DISK DEVICE TAG OFFSET LENGTH FLAGS
ARG01-05_CU0212 c3t110d2s2 c3t110d2 25186048 2076928 -
ARG03-15_CU0561 c3t110d0s2 c3t110d0 16777216 4171520 -
ARG03-15_CU0562 c3t110d1s2 c3t110d1 4194304 16754432 -


cat out | nawk -F" " '/[0-9]+/ { sum += $5 ; print $sum}'

Above is the nawk that I am trying. Firstly check it's a number, and then addition up column 5. I read a few random web-pages, and I thought this would work, but does'nt...

I am using nawk on Solaris although I think that nawk exists on many Linux distributions too.

Many thanks for any tips.