[ale] fun with processes

[Eric Z. Ayers]

Hi Ben,

Ben Phillips writes:
 > On Thu, 5 Aug 1999, Eric Z. Ayers wrote:
 > 
 > > Ben Phillips writes:
 > >  > Is there a way to resume a backgrounded process from a shell other than
 > >  > the one that initiated it?  If not, why?
 > >
 > > You can use kill -STOP <pid> to suspend a process and kill -CONT <pid> 
 > > to resume it.  So you have to know the pid and have permissions to
 > > send the task a signal.
 > 
 > This doesn't work, BTW.  Not from a shell other than the one that initiated
 > the process.  I'm still looking into this 'screen' thing.  But really I was
 > curious about the underlying architectural limitations.  What about a
 > process is so tied to the shell that launched it that UNIX can't easily
 > allow another shell to resume the process?

Are you sure you are using the 'pid' and not the job number?


in one window

$ ./mytest
Hello World!
Hello World!


In another window:

[eric at cricket eric]$ ps auxww | grep mytest
eric     32718  0.0  0.4   720   264  p6 S    10:09   0:00 ./mytest
[eric at cricket eric]$ kill -STOP 32718
[eric at cricket eric]$ kill -CONT 32718     

(what I saw in the first window)
Hello World!
Hello World!

[1]+  Stopped (signal)        ./mytest
[eric at cricket eric]$ Hello World!
Hello World!
Hello World!
Hello World!