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 later, or Python 3.x
Unix or Linux platform.
Test
Python 2.6.9
Python 2.7.8
Python 3.1.5
Python 3.2.5
Python 3.3.5
Python 3.4.1
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)
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.
Development
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
Project details
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unix_daemon-1.0.0.tar.gz
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