Shell Scripts

Shell Scripts

It's a real shame people don't know how to use AWK properly. It's a fairly capable little language. One of the common abuses is piping grep to AWK - as AWK applies regexes itself to every line[1]. Basically, if we can assume input tends not to be huge or that most the input will be acted on, then whenever you see:

grep XYZ | awk ... '{ ... }'

You'd be much better off with:

awk ... '/XYZ/ { .... }'

E.g. Your shell example could be done with:

find /path -name someglob | xargs awk '/^bar/ { print $2 }'

or using GNU find's built-in xargs-ish feature (when was that added?):

find /path -name someglob -exec awk '/^bar/ { print $2 }' {} +

This is meant more for the peanut gallery than for you ;) - I was expecting there'd be a rush to offer more optimal one-liners, strangely there hasn't been. ;)

1. Though, as Padraig Brady has shown me, beyond a certain size of file, there is a benefit to using grep to pre-filter input if you're discarding a sufficient amount of that input, as grep is much faster at processing each line than AWK.