Need a help to write a perl script

What is your definition of help to write? It appears that your question should read "Need you to write a perl script...".

Please post any code that you have already written, sample input, expected output, and actual output. Also read Markup in the Monastery (especially the section on <code>...</code> blocks).

I'm not familiar with 'HP OVO product' and so don't know the necessary reporting formats, and didn't see any affiliated modules on CPAN. I also don't know what definition of megabyte you are using. I would expect -s will be useful, as will opendir and readdir. That chunk may look something like (untested):

my $dir = 'somewhere';
opendir my $dh, $dir or die $!;
while (my $file = readdir $dh) {
    print "Too big: $file\n" if -s "$dir/$file" > 1024**2
}
[download]

You may also want to look at File::Find.

If you know the directory, then do I understand right that this is just a matter of checking if any file (possibly with some filename filtering specifications) is growing beyond the 1 MB limit?

How often do you need to check

The File::Find module is an option, but for such an easy task (no need to walk through subdirectories, I understand), you might as well write a procedure reading the directory and finding files matching your conditions.

Ah, yes, as a final question, have you tried something?

Otherwise, I do not know any thing about the "HP OVO product", if this is important to your question, I may be off-topic.

See HP OpenView for more information/links. Regards, Karl

Update:

Using a well know search engine, i found CSOV.

I didn't use this product and it's expensive but perhaps it's worth to take a look at.

And perhaps a fellow monk has some experience with this product and likes to say something about it?

I prefer Nagios and it's splendid fork Icinga for tasks like this.

Have you searched the PM site for previous related discussions? Here, for example, is one: unable to monitor file size change with win32::changenotify. It is tailored to Win32 file systems, but as others have noted, you haven't given us much to run on.