Obtain patterns in one file from another using ack or awk or better way than grep?

Question

Is there a way to obtain patterns in one file (a list of patterns) from another file using ack as the -f option in grep? I see there i

Answer 1

You can convert the file into a regex for ack with tr. I used sed to remove the trailing pipe character.

ack "`tr '\n' '|' < patts | sed 's/.$//'`"

Note you need a couple of processes for this so the awk solution is probably more efficient, but this is quite easy to remember.