#! /usr/bin/perl

use strict;
use warnings;
use Tie::File;

my $file = 'test.txt';
tie my @array,'Tie::File',$file or die $!;
foreach my $line(@array){
  $line =~ s~\$res = system("/prj/sw/tool")~\$res = system("/prj/vlsit
+/toolsmodule")~;
}
untie @array;
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