/ 
JIP-Daemon-0.041
River stage zero No dependents
/ JIP::Daemon

NAME

JIP::Daemon - Daemonize server process.

VERSION

This document describes JIP::Daemon version 0.041.

SYNOPSIS

Just run:

use JIP::Daemon;

my $proc = JIP::Daemon->new;

# Send program to backgroung.
$proc = $proc->daemonize;

# In the backgroung process:
$proc->is_detached; # 1
$proc->try_kill(0); # 1
printf qq{pid(%s), is_alive(%d), is_detached(%d)\n}, $proc->status;

# If the program is already a running background job, the daemonize method shall have no effect.
$proc = $proc->daemonize;

Dry run:

use JIP::Daemon;

my $proc = JIP::Daemon->new(dry_run => 1);

$proc->daemonize;

# In the same process
$proc->is_detached; # 0

With logger:

use Mojo::Log;
use JIP::Daemon;

my $proc = JIP::Daemon->new(logger => Mojo::Log->new);

$proc->daemonize;

With on_fork_callback:

use JIP::Daemon;

my $proc = JIP::Daemon->new(
    on_fork_callback => sub {
        # After daemonizing, and before exiting,
        # run the given code in parent process
        print $proc->pid;
    },
)->daemonize;

ATTRIBUTES

JIP::Daemon implements the following attributes.

pid

my $pid = $proc->pid;

is_detached

my $is_detached => $proc->is_detached;

Process is detached from the controlling terminal.

dry_run

my $dry_run = $proc->dry_run;

Perform a trial run with no changes made (foreground if dry_run).

uid

my $uid = $proc->uid;

The real user identifier and the effective user identifier for this process.

gid

my $gid = $proc->gid;

The real group identifier and the effective group identifier for this process.

cwd

my $cwd = $proc->cwd;

Change the current working directory.

umask

my $umask = $proc->umask;

Most Daemon processes runs as super-user, for security reasons they should protect files that they create. Setting user mask will prevent unsecure file priviliges that may occur on file creation.

logger

JIP::Daemon->new(logger => Mojo::Log->new)->logger->info('Hello');

Simple logger, based on Mojo::Log interface.

log_callback

With default callback:

my $proc = JIP::Daemon->new(logger => Mojo::Log->new);

# $proc->logger->info('Hello');
$proc->log_callback->($proc, 'Hello');

# $proc->logger->info(sprintf 'format %s', 'line');
$proc->log_callback->($proc, 'format %s', 'line');

With custom callback:

my $proc = JIP::Daemon->new(
    logger       => Mojo::Log->new,
    log_callback => sub {
        my ($proc, @lines) = @_;
        $proc->logger->debug(@lines);
    },
);
$proc->log_callback->($proc, 'Hello');

on_fork_callback

After daemonizing, and before exiting, run the given code in parent process.

devnull

my $devnull = $proc->devnull;

Returns a string representation of the null device.

stdout

my $stdout = $proc->stdout;

If this parameter is supplied, redirect STDOUT to file.

stderr

my $stderr = $proc->stderr;

If this parameter is supplied, redirect STDERR to file.

program_name

my $program_name = $proc->program_name;

Returns a string with name of the process.

SUBROUTINES/METHODS

new

my $proc = JIP::Daemon->new;
my $proc = JIP::Daemon->new(dry_run => 1);

Construct a new JIP::Daemon object.

daemonize

$proc = $proc->daemonize;

Daemonize server process.

reopen_std

$proc = $proc->reopen_std;

Reopen STDIN, STDOUT, STDERR to /dev/null.

my $proc = JIP::Daemon->new(
    stdout => '+>/path/to/out.log',
    stderr => '+>/path/to/err.log',
);

$proc = $proc->reopen_std;

The stdout and stderr arguments are file names that will be opened and be used to replace the standard file descriptors. These special modes only work with two-argument form of open.

drop_privileges

my $proc = JIP::Daemon->new(uid => 1000, gid => 1000, umask => 0, cwd => q{/});
$proc = $proc->drop_privileges;

Change uid/gid/umask/cwd on demand.

try_kill

my $is_alive = $proc->try_kill(0);

This is identical to Perl's builtin kill() function for sending signals to processes (often to terminate them).

change_program_name

my $proc = JIP::Daemon->new(program_name => 'tratata');
$proc = $proc->change_program_name;

Changes the name of the program.

status

my ($pid, $is_alive, $is_detached) = $proc->status;

Returns a list of process attributes: PID, is alive, is detached (in backgroung).

DIAGNOSTICS

None.

CONFIGURATION AND ENVIRONMENT

JIP::Daemon requires no configuration files or environment variables.

SEE ALSO

POSIX, Privileges::Drop, Object::ForkAware, Proc::Daemon, Daemon::Daemonize.

AUTHOR

Vladimir Zhavoronkov, <flyweight at yandex.ru>

LICENSE AND COPYRIGHT

Copyright 2015-2018 Vladimir Zhavoronkov.

This program is free software; you can redistribute it and/or modify it under the terms of the the Artistic License (2.0). You may obtain a copy of the full license at:

http://www.perlfoundation.org/artistic_license_2_0

Any use, modification, and distribution of the Standard or Modified Versions is governed by this Artistic License. By using, modifying or distributing the Package, you accept this license. Do not use, modify, or distribute the Package, if you do not accept this license.

If your Modified Version has been derived from a Modified Version made by someone other than you, you are nevertheless required to ensure that your Modified Version complies with the requirements of this license.

This license does not grant you the right to use any trademark, service mark, tradename, or logo of the Copyright Holder.

This license includes the non-exclusive, worldwide, free-of-charge patent license to make, have made, use, offer to sell, sell, import and otherwise transfer the Package with respect to any patent claims licensable by the Copyright Holder that are necessarily infringed by the Package. If you institute patent litigation (including a cross-claim or counterclaim) against any party alleging that the Package constitutes direct or contributory patent infringement, then this Artistic License to you shall terminate on the date that such litigation is filed.

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