Sending signal 0 to a pid will raise an OSError exception if the pid is not running, and do nothing otherwise. import os def check_pid(pid): “”” Check For the existence of a unix pid. “”” try: os.kill(pid, 0) except OSError: return False else: return True
$$ is defined to return the process ID of the parent in a subshell; from the man page under “Special Parameters”: $ Expands to the process ID of the shell. In a () subshell, it expands to the process ID of the current shell, not the subshell. In bash 4, you can get the process … Read more
The variable $$ contains the PID.
The pid files contains the process id (a number) of a given program. For example, Apache HTTPD may write its main process number to a pid file – which is a regular text file, nothing more than that – and later use the information there contained to stop itself. You can also use that information … Read more
The best way is: if ps -p $PID > /dev/null then echo “$PID is running” # Do something knowing the pid exists, i.e. the process with $PID is running fi The problem with kill -0 $PID is that the exit code will be non-zero even if the process is running and you don’t have permission … Read more
There exists no platform-independent way that can be guaranteed to work in all jvm implementations. ManagementFactory.getRuntimeMXBean().getName() looks like the best (closest) solution, and typically includes the PID. It’s short, and probably works in every implementation in wide use. On linux+windows it returns a value like “12345@hostname” (12345 being the process id). Beware though that according … Read more
There are many services, which can listen port 80 on windows. Luckily you can detect and stop them all running simple console command: NET stop HTTP When you’ll start it, you will get list first: To avoid this problem in future go to Local Services and disable listed services. N.B. – Some services will restart … Read more
You need to save the PID of the background process at the time you start it: foo & FOO_PID=$! # do other stuff kill $FOO_PID You cannot use job control, since that is an interactive feature and tied to a controlling terminal. A script will not necessarily have a terminal attached at all so job … Read more