From: Joel VanderWerf <vjoel@...>
Date: 2009-05-15T06:30:10+09:00
Subject: Re: Can you get the 1st occurrence of  a value using grep?

Mmcolli00 Mom wrote:
> Can you get a 1st occurence of a sting inside a huge text file?
> 
> For instance, I  know that there will be 1 or more occurrences of a the
> string 'fail' in a text file and I only want to get the first line
> containing the 'fail' instead of getting every line with a fail. My
> program reads over 100 files that may contain one or more 'fail' values.
> 
> Thanks
> MC
> 
> Dir["//MYFile/*.txt"].each do |textfile|
>     getGrepOffense = textfile.grep(/fail/)
>     strOffense = getGrepOffense.join
>     puts strOffense
> end

[~/tmp] cat grepfail.rb
DATA.grep /fail/ do |line|
   p line
   break
end

__END__
ok 1
ok 2
fail 1
ok 3
fail 2
fail 3
[~/tmp] ruby grepfail.rb
"fail 1\n"

This should work with an open File in place of DATA.

-- 
       vjoel : Joel VanderWerf : path berkeley edu : 510 665 3407