what does this one do?


cat $FOR_FIL | grep PAY | cut -c 92-106 | tail -$i

It finds(greps) lines having PAY in $FOR_FIL(file) and gets the characters from 92-106 and gives the last 'i' lines as the output.

Instead of cat $FOR_FIL, you could use - grep PAY $FOR_FIL which is a good way of scripting.

does its function just the same?

It achieves the same functionality. May be you should 'man grep' and see for yourself.