# constants
use constant ADD_RESULT          => 105;
use constant BIND_RESULT         => 97;
use constant COMPARE_RESULT      => 111;
use constant DELETE_RESULT       => 107;
use constant MODIFY_RESULT       => 103;
use constant SEARCH_RESULT_DONE  => 101;
use constant PROGRAM_NAME        => "sun2unboundid.pl";

http://docstore.mik.ua/orelly/perl3/prog/ch31_07.htm

How to use a constant in perl

Using constants in perl

perl

Perl