[wellylug] Some help with grep

[Rob Stockley]

On Sunday 20 June 2004 11:24, David Antliff wrote:
> On Sun, 20 Jun 2004, Jamie Dobbs wrote:
> > Is there any way with grep that I can search for certain instances of
> > a string (in this case an email domain) but not include a certain
> > address.
> >
> > ie. I want to find all occurances of @domain.co.nz in the file but have
> > it ignore any instances of this_address at domain.co.nz
>
> cat thefile | grep '@domain.co.nz' | grep -v 'this_address at domain.co.nz'

using cat first is almost always unnecessary in a pipe. Reduce the number of 
key presses required by passing thefile directly to the first grep, ala

grep '@domain.co.nz' thefile | grep -v 'this_address at domain.co.nz'

I used cat all the time until I had this pointed out to me one day.

HTH,
Rob