sub translate_ifindex() {
    my $ports_ini_dir = "/home/portal/bin/conf/snmp_set";

    my (@range_files) =
      ( [ 204, 381, "snmp_ports_slot02.txt", ]
        [ 22,   199,  "snmp_ports_slot04.txt", ]
        [ 513,  690,  "snmp_ports_slot06.txt", ]
        [ 823,  1000, "snmp_ports_slot08.txt", ]
        [ 1067, 1244, "snmp_ports_slot10.txt", ]
        [ 1311, 1488, "snmp_ports_slot12.txt", ]
        [ 1555, 1732, "snmp_ports_slot14.txt", ]
        [ 1799, 1976, "snmp_ports_slot16.txt", ]
        [ 2043, 2220, "snmp_ports_slot18.txt", ]
        [ 2287, 2464, "snmp_ports_slot20.txt", ] );

    for ( my $t = 0 ; $t < @ifindex ; $t++ ) {
        for my $range_file (@range_files) {
            if (   $ifindex[$t] >= $$range_file[0]
                && $ifindex[$t] <= $$range_file[1] )
            {
                my $cfg = new Config::IniFiles(
                    -file => "$ports_ini_dir/$$range_file[2]" );
                if ($cfg) {
                    push @msan_slot, $cfg->val( $ifindex[$t], "slot");
                    push @msan_port, $cfg->val( $ifindex[$t], "port");
                }
                else {
                    warn "Ooops($$range_file[2]): @Config::IniFiles::e
+rrors";
                }
            }
        }
    }
}
[download]

Error message tells you why.