Net::Server::Daemonize

Section: User Contributed Perl Documentation (3)
Updated: 2021-01-27
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NAME

Net::Server::Daemonize - Safe fork and daemonization utilities

SYNOPSIS

    use Net::Server::Daemonize qw(daemonize);

    daemonize(
      'nobody',                 # User
      'nobody',                 # Group
      '/var/state/mydaemon.pid' # Path to PID file - optional
    );

DESCRIPTION

This module is intended to let you simply and safely daemonize your server on systems supporting the POSIX module. This means that your Perl script runs in the background, and it's process ID is stored in a file so you can easily stop it later.

EXPORTED FUNCTIONS

daemonize: Main routine. Arguments are user (or userid), group (or group id or space delimited list of groups), and pid_file (path to file). This routine will check on the pid file, safely fork, create the pid file (storing the pid in the file), become another user and group, close STDIN, STDOUT and STDERR, separate from the process group (become session leader), and install $SIG{INT} to remove the pid file. In otherwords - daemonize. All errors result in a die. As of version 0.89 the pid_file is optional.
safe_fork: Block SIGINT during fork. No arguments. Returns pid of forked child. All errors result in a die.
set_user: Become another user and group. Arguments are user (or userid) and group (or group id or space delimited list of groups).
set_uid: Become another user. Argument is user (or userid). All errors die.
set_gid: Become another group. Arguments are groups (or group ids or space delimited list of groups or group ids). All errors die.
get_uid: Find the uid. Argument is user (userid returns userid). Returns userid. All errors die.
get_gid: Find the gids. Arguments are groups or space delimited list of groups. All errors die.
is_root_user: Determine if the process is running as root. Returns 1 or undef.
check_pid_file: Arguments are pid_file (full path to pid_file). Checks for existance of pid_file. If file exists, open it and determine if the process that created it is still running. This is done first by checking for a /proc file system and second using a ``ps'' command (BSD syntax). (If neither of these options exist it assumed that the process has ended) If the process is still running, it aborts. Otherwise, returns true. All errors die.
create_pid_file.: Arguments are pid_file (full path to pid_file). Calls check_pid_file. If it is successful (no pid_file exists), creates a pid file and stores $$ in the file.
unlink_pid_file: Does just that.

AUTHORS

Jeremy Howard <j+daemonize@howard.fm>

Program flow, concepts and initial work.

Paul Seamons <paul@seamons.com>

Code rework and componentization. Ongoing maintainer.

LICENSE

  This package may be distributed under the terms of either the
  GNU General Public License
    or the
  Perl Artistic License

  All rights reserved.