No shell prompt message, just a blinking cursor after starting a Python script as a daemon?

daemon, python, python-daemon

Solution

You can get your expected beahviour by change

self.stdout_path = '/dev/tty'
self.stderr_path = '/dev/tty'

to:

self.stdout_path = '/dev/null'
self.stderr_path = '/dev/null'

I recommend to write a init script using shell script in your case.

FYI, I can not find any document of `runner` except its source code.

Problem

- python-daemon-1.5.2-1.el6.noarch Below is the script that I received from a developer: ``` import threading import multiprocessing, os, signal, time, Queue import time from suds.client import Client from hotqueue import HotQueue from config import config queue = HotQueue(config['redis_hotqueue_list'], host=config['redis_host'], port=int(config['redis_port']),password=config['redis_pass'], charset="utf-8",db=0) @queue.worker() def sendMail(item): key = item[0] domain = item[1] fromemail = item[2] fromname = item[3] subject = item[4] content = item[5] toemail = item[6] cc = item[7] bcc = item[8] replyto = item[9] # Convert to string variable url = config['sendmail_tmdt_url'] client = Client(url) client.service.send_mail(key,domain, fromemail,subject, content, toemail,fromname, '','',''); for i in range(10): t = threading.Thread(target=sendMail) t.setDaemon(True) t.start() while True: time.sleep(50) ``` As you can see, he's using the threading module to make it can be run as a daemon. I'm going to switch to use the daemon library follow this blog post. Here's my first try: ``` from daemon import runner import logging import time import threading import multiprocessing, os, signal, time, Queue import time from suds.client import Client from hotqueue import HotQueue from config import config class Mail(): def __init__(self): self.stdin_path = '/dev/null' self.stdout_path = '/dev/tty' self.stderr_path = '/dev/tty' self.pidfile_path = '/var/run/sendmailworker/sendmailworker.pid' self.pidfile_timeout = 1 def run(self): while True: queue = HotQueue(config['redis_hotqueue_list'], host=config['redis_host'], port=int(config['redis_port']), password=config['redis_pass'], charset=r"utf-8", db=0) @queue.worker() def sendMail(item): key = item[0] domain = item[1] fromemail = item[2] fromname = item[3] subject = item[4] content = item[5] toemail = item[6] cc = item[7] bcc = item[8] replyto = item[9] # Convert to string variable url = config['sendmail_tmdt_url'] client = Client(url) client.service.send_mail(key,domain, fromemail,subject, content, toemail, fromname, '', '', ''); logger.debug("result") #sleep(50) mail = Mail() logger = logging.getLogger("sendmailworker") logger.setLevel(logging.INFO) formatter = logging.Formatter("%(asctime)s - %(name)s - %(levelname)s - %(message)s") handler = logging.FileHandler("/var/log/sendmailworker/sendmailworker.log") handler.setFormatter(formatter) logger.addHandler(handler) daemon_runner = runner.DaemonRunner(mail) daemon_runner.daemon_context.files_preserve=[handler.stream] daemon_runner.do_action() ``` It works but I have to press the Ctrl-C to get the shell prompt after starting: `/etc/init.d/sendmailworker start` ``` Starting server # started with pid 2586 ^C # ``` How can I get rid of this problem? Append an ampersand doesn't help: ``` # /etc/init.d/sendmailworker start & [1] 4094 # Starting server started with pid 4099 ^C [1]+ Done /etc/init.d/sendmailworker start # ``` As @Celada pointed out: actually, I already had my shell prompt, but it doesn't display `[root@hostname ~]#` as usual, just a blinking cursor. Simple pressing Enter make my shell prompt reappear. So the question should be: how to make the `started with pid xxxxx` come first, at the same line with `Starting server`, then display my shell prompt? The `stop` function is working fine: ``` [root@hostname ~]# /etc/init.d/sendmailworker stop Stopping server Terminating on signal 15 [root@hostname ~]# ``` How can I do the similar for the `start` function? Something like this: ``` [root@hostname ~]# /etc/init.d/sendmailworker start Starting server started with pid 30624 [root@hostname ~]# ```

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