[CentOS] Extract lines from text file

Wed Aug 15 19:40:16 UTC 2012
Tony Molloy <tony.molloy at ul.ie>

On Wednesday 15 August 2012 19:46:42 Les Mikesell wrote:
> On Wed, Aug 15, 2012 at 1:26 PM, Tony Molloy <tony.molloy at ul.ie> 
> >> ]$ cat testcentoslist | egrep ^m.*:.*:.*:850:
> >> m9718308:pw:9301:850: Lynch  :/home/pgstud/m9718508:/bin/bash
> >
> > Exactly what I needed. I'll just drop the cat as a later poster
> > pointed out.
> sed -n -e '/pattern/p' can match anything grep would do and might
>  be even more useful if you want substitutions for subsequent use. 
>  And of course perl can do anything sed can do, and then some...

True true, and of course C could do anything and everything ;-)

But all I need is a simple script which will be run once a year to 
remove the graduated students from the password file.