Hi xiaoyafeng,

You have to take a look at Tie::File and perlre.

From the documentation:

A sample code to proceed....

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

my @file;

tie @file, 'Tie::File', "test.txt" or die "$!";

for (0..5) {

print "ORA is present\n" if $file[$_] =~ /ORA/;

}
[download]

update: added code.