exclude list from list

[joe]

Hello is there a quick way to produce a list of emails that subtracts
a small list emails from a big list. Thanks.

 

[it_says_BALLS_on_your forehead]

Hello is there a quick way to produce a list of emails that subtracts
a small list emails from a big list. Thanks.

shove the big list in a hash, then for each item in the small list,
delete it from the hash.

 

[Paul Lalli]

Hello is there a quick way to produce a list of emails that subtracts
a small list emails from a big list. Thanks.

$ perldoc -q "difference of two arrays"
Found in /opt2/Perl5_8_4/lib/perl5/5.8.4/pod/perlfaq4.pod
How do I compute the difference of two arrays? How do I
compute the intersection of two arrays?

Use a hash. Here's code to do both and more. It assumes
that each element is unique in a given array:

@union = @intersection = @difference = ();
%count = ();
foreach $element (@array1, @array2) { $count{$element}++ }
foreach $element (keys %count) {
push @union, $element;
push @{ $count{$element} > 1 ? \@intersection :
\@difference }, $element;
}

Note that this is the symmetric difference, that is, all
elements in either A or in B but not in both. Think of it
as an xor operation.