`daemonize` — Daemonize Current Process (Unix only)#

Module to daemonize the current process on POSIX systems.

This module provides a function daemonize() to turn the current Python process into a background daemon process on POSIX-compatible operating systems (Linux, macOS, FreeBSD) but not on not WASI Android or iOS. It uses the standard double-fork technique to detach the process from the controlling terminal and optionally closes or redirects standard streams.

Double-fork diagram:

Original process (parent)
├── fork()  → creates first child
│   └─ Parent exits via os._exit() → returns control to terminal
│
└── First child
    ├── os.setsid()  → becomes session leader (detaches from terminal)
    ├── fork()  → creates second child (grandchild)
    │   └─ First child exits → ensures grandchild is NOT a session leader
    │
    └── Second child (Daemon)
        ├── is_daemon = True
        ├── Optionally close/redirect standard streams
        ├── Optionally change working directory
        └── # Daemon continues here
            while True:
                do_background_work()

The “while True” loop represents the main work of the daemon:

It runs indefinitely in the background
Performs tasks such as monitoring files, processing data, or logging
Everything after daemonize() runs only in the daemon process

Example usage:

import time
from pywikibot.daemonize import daemonize

def background_task():
    while True:
        print("Daemon is working...")
        time.sleep(5)

daemonize()

# This code only runs in the daemon process
background_task()

class daemonize.StandardFD(*values)[source]#

Bases: IntEnum

File descriptors for standard input, output and error.

STDERR = 2#

STDIN = 0#

STDOUT = 1#

daemonize.daemonize(*, close_fd=True, chdir=True, redirect_std=None)[source]#

Daemonize the current process.

Only works on POSIX compatible operating systems. The process will fork to the background and return control to terminal.

Changed in version 10.6: raises NotImplementedError instead of AttributeError if daemonize is not available for the given platform. Parameters must be given as keyword-only arguments.

Caution

Do not use it in multithreaded scripts or in a subinterpreter.

Parameters:

close_fd (bool) – Close the standard streams and replace them by /dev/null
chdir (bool) – Change the current working directory to /
redirect_std (str | None) – Filename to redirect stdout and stdin to

Raises:

RuntimeError – Must not be run in a subinterpreter
NotImplementedError – Daemon mode not supported on given platform

Return type:

None

daemonize — Daemonize Current Process (Unix only)#

`daemonize` — Daemonize Current Process (Unix only)#