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MooseX::Daemonize(3pm) User Contributed Perl Documentation MooseX::Daemonize(3pm)


MooseX::Daemonize - Role for daemonizing your Moose based application


version 0.22


    package My::Daemon;
    use Moose;
    with qw(MooseX::Daemonize);
    # ... define your class ....
    after start => sub {
        my $self = shift;
        return unless $self->is_daemon;
        # your daemon code here ...
    # then in your script ...
    my $daemon = My::Daemon->new_with_options();
    my ($command) = @{$daemon->extra_argv}
    defined $command || die "No command specified";
    $daemon->start   if $command eq 'start';
    $daemon->status  if $command eq 'status';
    $daemon->restart if $command eq 'restart';
    $daemon->stop    if $command eq 'stop';


Often you want to write a persistent daemon that has a pid file, and responds appropriately to Signals. This module provides a set of basic roles as an infrastructure to do that.


The maintainers of this module now recommend using Daemon::Control instead.


When going into background MooseX::Daemonize closes all open file handles. This may interfere with you logging because it may also close the log file handle you want to write to. To prevent this you can either defer opening the log file until after start. Alternatively, use can use the 'dont_close_all_files' option either from the command line or in your .sh script.

Assuming you want to use Log::Log4perl for example you could expand the MooseX::Daemonize example above like this.

    after start => sub {
        my $self = shift;
        return unless $self->is_daemon;
        my $logger = Log::Log4perl->get_logger();
        $logger->info("Daemon started");
        # your daemon code here ...


This list includes attributes brought in from other roles as well we include them here for ease of documentation. All of these attributes are settable though MooseX::Getopt's command line handling, with the exception of "is_daemon".

The name of our daemon, defaults to "$package_name =~ s/::/_/";
The base for our PID, defaults to "/var/run/"
The directory we chdir to; defaults to "/".
The file we store our PID in, defaults to "$pidbase/$"
If true, the process won't background. Useful for debugging. This option can be set via Getopt's -f.
If true, the process will not perform the typical double-fork, which is extra added protection from your process accidentally acquiring a controlling terminal. More information can be found by Googling "double fork daemonize".
If true, the process will not clean up zombie processes. Normally you don't want this.
If true, the objects open filehandles will not be closed when daemonized. Normally you don't want this.
If true, the process is the backgrounded daemon process, if false it is the parent process. This is useful for example in an "after 'start' =" sub { }> block.

NOTE: This option is explicitly not available through MooseX::Getopt.

Number of seconds to wait for the process to stop, before trying harder to kill it. Defaults to 2 seconds.

These are the internal attributes, which are not available through MooseX::Getopt.


Daemon Control Methods

These methods can be used to control the daemon behavior. Every effort has been made to have these methods DWIM (Do What I Mean), so that you can focus on just writing the code for your daemon.

Extending these methods is best done with the Moose method modifiers, such as "before", "after" and "around".

Setup a pidfile, fork, then setup the signal handlers.
Stop the process matching the pidfile, and unlinks the pidfile.
Literally this is:


Pidfile Handling Methods

This method will create a MooseX::Daemonize::Pid::File object and tell it to store the PID in the file "$pidbase/$".
This checks to see if the daemon process is currently running by checking the pidfile.
Returns the PID of the daemon process.
Write the pidfile.
Removes the pidfile.

Signal Handling Methods

Setup the signal handlers, by default it only sets up handlers for SIGINT and SIGHUP. If you wish to add more signals just use the "after" method modifier and add them.
Handle a INT signal, by default calls "$self-"stop()>
Handle a HUP signal. By default calls "$self-"restart()>

Exit Code Methods

These are overridable constant methods used for setting the exit code.

Returns 0.
Returns 1.


The meta() method from Class::MOP::Class


Moose, MooseX::Getopt, MooseX::Types::Path::Class and POSIX


Obviously this will not work on Windows.


Daemon::Control, Proc::Daemon, Daemon::Generic


Mike Boyko, Matt S. Trout, Stevan Little, Brandon Black, Ash Berlin and the #moose denizens

Some bug fixes sponsored by Takkle Inc.


Bugs may be submitted through the RT bug tracker <> (or <>).

There is also a mailing list available for users of this distribution, at <>.

There is also an irc channel available for users of this distribution, at "#moose" on "" <irc://>.


  • Stevan Little <>
  • Chris Prather <>


  • Karen Etheridge <>
  • Michael Reddick <>
  • Yuval Kogman <>
  • Ash Berlin <>
  • Brandon L Black <>
  • Jonathan Sailor <>
  • David Steinbrunner <>
  • Michael Schwern <>
  • Shoichi Kaji <>
  • Dave Rolsky <>
  • Chisel Wright <>


This software is copyright (c) 2007 by Chris Prather.

This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.

2019-12-07 perl v5.40.0