How to Get the Process Id to Kill a Nohup Process

How to get the process ID to kill a nohup process?

When using nohup and you put the task in the background, the background operator (&) will give you the PID at the command prompt. If your plan is to manually manage the process, you can save that PID and use it later to kill the process if needed, via kill PID or kill -9 PID (if you need to force kill). Alternatively, you can find the PID later on by ps -ef | grep "command name" and locate the PID from there. Note that nohup keyword/command itself does not appear in the ps output for the command in question.

If you use a script, you could do something like this in the script:

nohup my_command > my.log 2>&1 &
echo $! > save_pid.txt

This will run my_command saving all output into my.log (in a script, $! represents the PID of the last process executed). The 2 is the file descriptor for standard error (stderr) and 2>&1 tells the shell to route standard error output to the standard output (file descriptor 1). It requires &1 so that the shell knows it's a file descriptor in that context instead of just a file named 1. The 2>&1 is needed to capture any error messages that normally are written to standard error into our my.log file (which is coming from standard output). See I/O Redirection for more details on handling I/O redirection with the shell.

If the command sends output on a regular basis, you can check the output occasionally with tail my.log, or if you want to follow it "live" you can use tail -f my.log. Finally, if you need to kill the process, you can do it via:

kill -9 `cat save_pid.txt`
rm save_pid.txt

Kill with nohup process ID

You don't need nohup. It does exactly two things:

Any of stdin, stdout or stderr that are attached to the TTY get redirected (to /dev/null in the stdin case, or to nohup.out in the stdout and stderr cases).
HUP signals received by nohup are not propagated to the child.

The first is just the same as normal shell redirection (but with a hardcoded destination, which you normally don't want anyhow). The second achieves the same goal as using disown -h to tell the shell not to propagate a HUP to the targeted child (which is default behavior in the first place when your shell is noninteractive).

Thus, you can avoid needing nohup entirely, with something like:

yourcommand </dev/null >/dev/null 2>&1 & yourcommand_pid=$!
disown -h "$yourcommand_pid"

...which lets you later run kill "$yourcommand_pid".

How to kill a nohup process?

kill -0 does not kill the process. It just checks if you could send a signal to it.

Simply kill pid, and if that doesn't work, try kill -9 pid.

Process ID of nohup process continually updating - cant kill process

Very very bad question ...

You are trying to kill you grep process...

ec2-user 16580 16153  0 19:50 pts/0    00:00:00 grep --color=auto nohup

The command is grep --color=auto nohup

I'm not sure you can kill nohup

nohup will run your command in a particular way. But after its launching, the nohup process dies.

How to Get the Process Id to Kill a Nohup Process