If the data's tab delimited, you could split your incoming line on tabs 

my @w = split(/\t/,$_);

[download]
and then build a key out of the first two fields and use that as your hash key 
if ( !$seen{$w[0].$w[1]}++ ) {

[download]

Alex / talexb / Toronto

"Groklaw is the open-source mentality applied to legal research" ~ Linus Torvalds

In reply to Re^3: Filtering very large files using Tie::File by talexb
in thread Filtering very large files using Tie::File by elef

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