Re: nohup command

[Bob Proulx]

Bernhard Voelker wrote:
> ravi kothari wrote:
> > when i am running my process with "nohup" command and exit from
> > the server and again login process is not alive,it is
> > killed.
> 
> Without more information, it's hard to guess.
> 
> What was the exact command line you were running?
> Is there something special about the server (firewalls, etc)?
> How do you login to that server (SSH)?

Yes.  The nohup command causes the SIGHUP signal to be ignored.  It
does not prevent other signals from being passed.  Therefore other
signals may still be killing the process.  It does not keep the files
open.  It explicitly redirects the standard descriptors to /dev/null
so that they are not attached to the terminal but other descriptors
are not affected.  Therefore if it is reading from other files then an
end of input on those files may affect the process.

The nohup command was written for use with the original AT&T Unix
systems before job control.  But the addition of BSD job control
changed the way the system operates.  The nohup command still does
exactly what it says it does but you might want to do something
different these days.

If you are trying launching a daemon program then there are additional
things that you need to do to make the program behave as a daemon.  I
would direct you to references if you are trying to launch a program
as a standalone daemon program.

Bob