You could just use an ancillary file:

use strict;

my $uuid_store = '/tmp/.uuid_store';
my $MY_UID=1;

if (-e $uuid_store) {
    open INHANDLE, "<$uuid_store" || die "Can't open $uuid_store for r
+ead\n";
    my $var = <INHANDLE>;
    close INHANDLE;
    $MY_UID = int $var;
}

print "The uid you are looking for : $MY_UID\n";

open OUTHANDLE, ">$uuid_store" || die "Can't open $uuid_store for writ
+e\n";
print OUTHANDLE ++$MY_UID;
close OUTHANDLE;
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Output:

% perl gen_uid.pl
The uid you are looking for : 1
% perl gen_uid.pl
The uid you are looking for : 2
% perl gen_uid.pl
The uid you are looking for : 3
% perl gen_uid.pl
The uid you are looking for : 4
% perl gen_uid.pl
The uid you are looking for : 5
% perl gen_uid.pl
The uid you are looking for : 6
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