Function emulating Daemon(3) on Linux and Unix OS.
Project description
unix_daemon is a python module emulating BSD daemon(3).
This module provides a function named daemon.
If this function is called, the process become a daemon and start to run background.
Requirements
Python 2.6 or 2.7
Unix or Linux platform.
Tested
Ubuntu 12.04 (x86_64)
CentOS 6.4 (x86_64)
Mac OS X 10.9
Setup
Install using pip
$ sudo pip install unix_daemon
Install from git.
$ git clone https://github.com/wbcchsyn/unix_daemon.git $ cd unix_daemon $ sudo python setup.py install
Usage
unix_daemon.daemon(nochdir=False, noclose=False)
The process become a daemon and start to run background.
- Arguments
If argument 1 ‘nochdir’ is False, the process changes the calling process’s current working directory to the root directory (“/”);Otherwise, the current working directory is left unchanged.The default value of the nochdir is False.If argument 2 ‘noclose’ is False, this function close file descriptor 0, 1 and 2, and then reopen /dev/null for file descriptor 0, 1 and 2./dev/null is opened even if some of the file descriptors are closed before called this function.If the value is True, file descriptor 0, 1, and 2 are left.The default value is False.- Return Value
daemon returns the pid of new process.
- Note
This function call fork internally to detach tty safely.Be careful to call this function when the more than two threads is run.(It is a good idea to call this function before creating a new thread.)- Example
Call unix_daemon.daemon(), then the process run backgrond.
import unix_daemon import os print('pid: %s\n' % os.getpid()) pid = unix_daemon.daemon() with file('/tmp/foo', 'a') as f: print('pid: %s\n' % os.getpid()) f.write('new pid: %s\n' % pid)You can see the process id changes and the 2nd print is not displayed.
Development
Install requirements to developing copy pre-commit hook from repository.
$ git clone git@github.com:wbcchsyn/unix_daemon.git $ cd unix_daemon $ pip install -r dev_utils/requirements.txt $ cp -p dev_utils/pre-commit .git/hook/