From: Brian Candler <b.candler@...>
Date: 2010-12-15T03:53:48+09:00
Subject: Re: Grep a string

Rajesh M. wrote in post #968323:
>  cat /tmp/cron.list | egrep '^[0-9\*]'
> 00 01 * * 0 (sync ; sync ; sync ; /sbin/reboot)
> 00 18 * * 6 (sync; sync; sync; /sbin/reboot)
>
> Not sure it is still getting digits, what am doing wrong here?

Grep shows the whole line which matches, or with the -o option shows the 
part of the line which matches the pattern. But you want to show the 
part of the line which *doesn't* match the pattern.

That's why people have been suggesting using sed, which edits the line:

sed 's/^[0-9* ]*//' /tmp/cron.list

But who needs sed when you have ruby?

ruby -pe 'sub! /^[\d* ]/,""' /tmp/cron.list

However that line relies on the ugly Perlism of special default 
operations on $_. Better to type a few more characters and be explicit:

cat /tmp/cron.list | ruby -ne 'puts $1 if /^[\d* ]+(.*)/'

cat /tmp/cron.list | ruby -ne 'puts $1 if /^[\d* ]+(.*)/ =~ $_'

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