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$ cat A; echo '* * * * *'; cat B
apple
...
lime
orange
banana

$ perl -e 'open F,$ARGV[0] or die;shift;my %set = map {$_ => 1 } <>; f
+or (<F>) {print if $set{$_}};' A B
lime

$ perl -e 'open F,$ARGV[0] or die;shift;my %set = map {$_ => 1 } <>; f
+or (<F>) {print unless $set{$_}};' A B
apple
cherry
carrot

$ cat C
grape
...
$ perl -e 'open F,$ARGV[0] or die;shift;my %set = map {$_ => 1 } <>; f
+or (<F>) {print if $set{$_}};' A B C
cherry
lime