[ILUG] sed question

[Niall O Broin]

On Thursday 19 February 2004, padraig.brady at corvil.com (Padraig Brady) wrote:

>OK I've a (very big) file like:
>
>0
>0
>1
>1
>2
>2
>3
>3
>:
>
>I would like to find and print the "2" lines,
>AND THEN STOP PRCOCESSING the humungous file.
>
>I was thinking of using sed, and the q command.

As is so often the case when sed is mentioned, and awk is suggested, the
correct answer is perl:


perl -ne 'if (/(^)(2)/) {print} else { exit if $2}' humungous_file


Before anyone jumps in - the () around the ^ are a tautology - I couldn't
resist having the checking variable be called $2.


Two characters less to type, and just a tiny bit less satisfying is:


perl -ne 'if (/1^(2)/) {print} else { exit if $1}' humungous_file




Niall