Verifying data change

[Anonymous Monk]

Currently I am fetching executable files from a web site. I only fetch when part of the executable name is changed. This has worked for the past year but now they changed the whole name. So I wanted to add to my script a part to notify me if they changed the whole name of the executable so I dont try and fetch some name that doesnt exist.

here is my current part of my script with the new name change:

my ($var) = $content =~ /(.{3}\-a99\-9)/;
$var = $1;

Now here is what I propose to add to my script so I am notified about a complete new filename:

if (not defined $var) 
{
    print "The whole name was changed so no match found.  You need to 
+change your reg expression.\n";
    exit 0;  #Since no match then exit the script.
}

I want advise on if this is the correct way to handle this?? Also "exit 0" means good exit? Or do I use "exit 1"??