zeek/testing/btest/doc/manual/data_struct_set_declaration.bro

# @TEST-EXEC: bro %INPUT
# @TEST-EXEC: btest-diff .stdout

event bro_init()
    {
    local ssl_ports: set[port];
    local non_ssl_ports = set( 23/tcp, 80/tcp, 143/tcp, 25/tcp );
    # SSH
    add ssl_ports[22/tcp];
    # HTTPS
    add ssl_ports[443/tcp];
    # IMAPS
    add ssl_ports[993/tcp];
    
    # Check for SMTPS 
    if ( 587/tcp !in ssl_ports )
        {
        add ssl_ports[587/tcp];
        }
    
    for ( i in ssl_ports )
        {
        print fmt("SSL Port: %s", i);
        }

    for ( i in non_ssl_ports )
        {
        print fmt("Non-SSL Port: %s", i);
        }
    }