Hi, I think you're missing the fact that the subtruct variable is not initialized and defaults to 0. So, what you get is
0 - 34523 - 9485 - 394 - 3456 = -47858 not 34523 - 9485 - 394 - 3456 = 21188 Cheers, Daniele igor denisov wrote: > Hello there. > > There is a problem here. > > input: > 34523 > 9485 > 394 > 3456 > > awk '{subtruct-=$1} END {print subtruct}' input > > output: > -47858 > same thing but without minus with > > awk '{sum+=$1} END {print sum}' input > > output: > 47858 > > Why in both cases the code sums the field? > -- > igor denisov.