use warnings;
use strict;
use Test::More;

# this is the regex we're working on
my $regex = qr/^ \s* (\d+) \s* \[(\d+)\] \s+ (\S+) \s+ \[(.+?)\] \s* (\w+): \s* (.*?) \s* $/x;

{
  ok my @out =
    # inside the q{} is the test input string
    q{ 20848[30892]    0000000000000000    [DM_MQ_I_DAEMON_START]info:  "Message queue daemon (tid : 27944, session 0102b20d80000456) is started sucessfully." }
    =~ $regex;
  is_deeply \@out,
    # inside the [] is the expected output (capture group matches)
    [ '20848', '30892', '0000000000000000', 'DM_MQ_I_DAEMON_START', 'info',
    q{"Message queue daemon (tid : 27944, session 0102b20d80000456) is started sucessfully."} ]
    or diag explain \@out;
}
# ... add more test cases here!

done_testing;