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.
- Python 2.6 or later, or Python 3.x
- Unix or Linux platform.
- Python 2.6.9
- Python 2.7.8
- Python 3.1.5
- Python 3.2.5
- Python 3.3.5
- Python 3.4.1
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
Make process daemon and start to run in the background.
- Arguments
If argument 1 'nochdir' is False, the process changes the callingprocess'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 descriptors 0,1 and 2 and redirect them to /dev/null. Even if some of them have beenclosed, this function open these file descriptors and redirect to/dev/null if noclose is False.The defult value of noclose is False.- Return Value
- daemon returns the pid of new process.
- Note
This function calls os.fork() internally to detach tty safely.Be careful to call this function when two or more than two python threadsare running.Normary, file descriptors 0, 1 and 2 are correspond to stdin, stdout andstderr. However, even if any of these file discriptors refer to somethingelse, they will still be closed when argument 'noclose' is False.It is a good idea to call this function before creating any threads andbefore opening any files or sockets.- Example
Call unix_daemon.daemon(), then the process starts to run in the backgrond.
import unix_daemon import os print('pid: %s\n' % os.getpid()) pid = unix_daemon.daemon() with open('/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.
Install requirements to developing copy pre-commit hook from repository.
$ git clone https://github.com/wbcchsyn/unix_daemon.git $ cd unix_daemon $ pip install -r dev_utils/requirements.txt $ ln -s ../../dev_utils/pre-commit .git/hooks/pre-commit