use a hash to count the number of each string occurance. 
#!/usr/bin/perl

while (<DATA>){
  chomp;
  $h{$_}++;  
}

for ( sort grep { $h{$_} != 1 } keys %h ) {
  print "$_\n";
}

__DATA__
A(01) 
B(02) 
C(03) 
A(01) 
D(04) 
E(05)

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Boris

In reply to Re: finding duplicate data by borisz
in thread finding duplicate data by harry34

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