For one thing, you can do something like: 
my @records = <BIGFILE>;

[download]
which will slurp but does not chomp at the same time; however, the impact of the CR will have little effect on your matching.

Since you then have to write out to a file, there's no need to wastefully add the carriage return before you split the file, so instead, you can do: 

my @records = <BIGFILE>;
my @london = grep /LONDON/, @records;
print LONDONFILE join "", @london;

[download]
Finally, this type of situation is an ideal one where slurping is inefficient, unless you're repeating the process multiple times; it's probably much easier and less of a memory hog to process line by line: 
while ( my $line = <BIGFILE> ) {
   /LONDON/ ? print LONDONFILE $line,"\n" : 
              print OTHERFILE  $line,"\n";
}

[download]

Updates as arturo pointed out to me that slurping in array mode doesn't chomp.

-----------------------------------------------------
Dr. Michael K. Neylon - mneylon-pm@masemware.com || "You've left the lens cap of your mind on again, Pinky" - The Brain
It's not what you know, but knowing how to find it if you don't know that's important

In reply to Re: Processing slurped file. by Masem
in thread Processing slurped file. by Jonathan

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