use strict;
use warnings;


my $inData = <<INDATA;
int abc;
.abc(abc);

INDATA

open my $in_fh1, '<', \$inData;

while (my $line = <$in_fh1>) {
   # if ($line =~ 
    if( my ($intro) = $line =~ /([.(]?abc)/g){
  
       print "${intro}_$_;\n" for 1 .. 2;
            
    }

   }
close $in_fh1;