NAME

Daemon::Daemonize - An easy-to-use daemon(izing) toolkit

VERSION

version 0.0052

SYNOPSIS

use Daemon::Daemonize qw/ :all /

daemonize( %options, run => sub {

# Daemon code in here...

} )

# Do some non-daemon stuff here...

You can also use it in the traditional way, daemonizing the current

process

daemonize( %options )

# Daemon code in here...

and use it to check up on your daemon:

# In your daemon

use Daemon::Daemonize qw/ :all /

        write_pidfile( $pidfile )
        $SIG{INT} = sub { delete_pidfile( $pidfile ) }

        ... Elsewhere ...

        use Daemon::Daemonize qw/ :all /

        # Return the pid from $pidfile if it contains a pid AND
        # the process is running (even if you don't own it), 0 otherwise
        my $pid = check_pidfile( $pidfile )

        # Return the pid from $pidfile, or undef if the
        # file doesn't exist, is unreadable, etc.
        # This will return the pid regardless of if the process is running
        my $pid = read_pidfile( $pidfile )

DESCRIPTION

Daemon::Daemonize is a toolkit for daemonizing processes and checking up on them. It takes inspiration from
<http://www.clapper.org/software/daemonize/>, MooseX::Daemon, Net::Server::Daemon

A note about the "close" option
If you're having trouble with IPC in a daemon, try closing only STD* instead of everything:

daemonize( ..., close => std, ... )

This is a workaround for a problem with using "Net::Server" and "IPC::Open3" in a daemonized process

USAGE

You can use the following functions in two ways, by either importing

them

use Daemon::Daemonize qw/ daemonize /

daemonize( ... )

or calling them as a class method:

use Daemon::Daemonize

Daemon::Daemonize->daemonize

daemonize( %options )
Daemonize the current process, according to %options:

        chdir <dir>         Change to <dir> when daemonizing. Pass undef for no chdir.
                            Default is '/' (to prevent a umount conflict)

        close <option>      Automatically close opened files when daemonizing:

                                1     Close STDIN, STDOUT, STDERR (usually redirected
                                      from/to /dev/null). In addition, close any other
                                      opened files (up to POSIX::SCOPEN_MAX)

                                0     Don't close anything

                                std   Only close STD{IN,OUT,ERR} (as in 1)

                            Default is 1 (close everything)

        stdout <file>       Open up STDOUT of the process to <file>. This will override any
                            closing of STDOUT

        stderr <file>       Open up STDERR of the process to <file>. This will override any
                            closing of STDERR

        run <code>          After daemonizing, run the given code and then exit

read_pidfile( $pidfile )
Return the pid from $pidfile. Return undef if the file doesn't exist, is unreadable, etc. This will return the pid regardless of if the process is running

For an alternative, see "check_pidfile"

check_pidfile( $pidfile )
Return the pid from $pidfile if it contains a pid AND the process is running (even if you don't own it), and 0 otherwise

This method will always return a number

write_pidfile( $pidfile, [ $pid ] )
Write the given pid to $pidfile, creating/overwriting any existing file. The second argument is optional, and will default to $$ (the current process number)

delete_pidfile( $pidfile )
Unconditionally delete (unlink) $pidfile

does_process_exist( $pid )
Using "kill", attempts to determine if $pid exists (is running).

If you don't own $pid, this method will still return true (by examining "errno" for EPERM).

For an alternative, see "can_signal_process"

can_signal_process( $pid )
Using "kill", attempts to determine if $pid exists (is running) and is owned (signable) by the user.

check_port( $port )
Returns true if $port on the localhost is accepting connections.

SEE ALSO

MooseX::Daemonize

Proc::Daemon

Net::Server::Daemonize

AUTHOR

Robert Krimen <robertkrimen@gmail.com>

COPYRIGHT AND LICENSE

This software is copyright (c) 2010 by Robert Krimen.

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