note
space_monk
<p>All of the above answers seem to have problems with possible filehandle limits; personally I would read the entire file and convert it to a hash of arrays, and then write each array out to a file indicated by the array key. This has the advantage that only one file is open at any time. I will stick my neck out and say it will also be faster due to less file I/O
<p>As a second comment, you should use something like [mod://Text::CSV] to get the data, but if you want it quick and dirty there's a good argument for using split instead of a regex here.</p>
<p><b>Amount of Data:</b> 300k rows = 64k per row = approx 19.6GB of data may cause problems, so maybe a compromise is to write the data when an array gets to a certain size.</p>
<p>The following (untested/debugged) shows the idea...it assumes you specify the file(s) you want to read from on the command line.</p>
<p><b>Update:</b> Changed when it writes to file as a result of a [davido] comment</p>
<code>
use constant ROW_LIMIT => 10000;
sub writeData {
my ($name, $data) = @_;
open FH, ">>", "sample_$name";
print FH @$data;
# may not be needed (auto close on sub end)
close FH;
}
my %hash;
my $ctr = 0;
while (<>) {
my @elems = split /|/;
my $idx = $elem[1];
if (exists $hash{$idx}) {
# save to existing array
push @$hash{$idx}, $_;
} else {
# create new array
$hash{$idx} = ( $_);
};
# if we've got too much data, write it out
if ($ctr++ >= ROW_LIMIT) {
# write data to each file...
foreach my $key (%hash) {
writeData( $key, $hash{ $key}); delete $hash{$key};
}
$ctr = 0;
}
}
# write remaining data to each file...
foreach my $key (%hash) {
writeData( $key, $hash{ $key});
}
</code>
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