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Background job not working as expected

 
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# 8  
Old 09-09-2014
GoodMorning Everybody,

This is what i did. Right click and "Open in Terminal". I have only opened a single terminal.

Test 1 with infinite.sh
==================

Code:
Shellscript:ls
infinite.sh
Shellscript:cat infinite.sh 
#!/bin/sh

while true
do
    echo "While infinite loop"
done
Shellscript:ps -a
  PID TTY          TIME CMD
 6700 pts/0    00:00:00 ps
Shellscript:ps -ef | grep infinite.sh 
root      6711  6518  0 21:56 pts/0    00:00:00 grep infinite.sh
Shellscript:./infinite.sh > /dev/null &
[1] 6770
Shellscript:ps -a
  PID TTY          TIME CMD
 6770 pts/0    00:00:05 infinite.sh
 6777 pts/0    00:00:0
Shellscript:exit   [Here i pressed enter]

The screen vanished after the exit statement.

Then i opened a new terminal.

Code:
Shellscript:ls
infinite.sh
Shellscript:ps -a
  PID TTY          TIME CMD
 7032 pts/1    00:00:00 ps
Shellscript:ps -ef | grep infinite
root      6770     1 90 21:56 ?        00:03:03 /bin/sh ./infinite.sh
root      7061  6955  0 22:00 pts/1    00:00:00 grep infinite

The background job did not get killed. It is still running with the same PID but now the parent is INIT.

Test 2 with sleep
==============

Code:
Shellscript:sleep 200 &
[1] 7253
Shellscript:exit

Opened a new terminal

Code:
Shellscript:ps -ef | grep sleep
root      7253     1  0 22:02 ?        00:00:00 sleep 200
root      7341  7293  0 22:03 pts/2    00:00:00 grep sleep

Here too the background job did not get killed. The command "jobs" didnot fetch anything. I suppose it is now not a background process any more.

Test 3 with sleep
============
Code:
Shellscript:sleep 800 &
[1] 8007
Shellscript:

Clicked on the cross mark of the window to close the session.

Opened a new terminal once more
Code:
Shellscript:ps -ef | grep sleep
root      8088  8048  0 22:08 pts/1    00:00:00 grep sleep

Now i don't see the sleep job running.

Test 4 with infinite loop
=======================

Code:
Shellscript:ps -ef | grep infinite
root      8398  8305  0 22:12 pts/1    00:00:00 grep infinite
Shellscript:./infinite.sh > /dev/null &
[1] 8425
Shellscript:ps -ef | grep infinite
root      8425  8305 86 22:12 pts/1    00:00:03 /bin/sh ./infinite.sh
root      8433  8305  0 22:12 pts/1    00:00:00 grep infinite

Clicked on the cross mark to close the terminal.

Opened a new terminal once more.

Code:
Shellscript:ps -ef | grep infinite.sh 
root      8497  8446  0 22:13 pts/0    00:00:00 grep infinite.sh

So if we close the session with clicking on the cross mark , then the process gets killed. But if we logout by exit, the process is not getting killed.

All the above tests are done with only one session opened at a particular time.

It seems it goes for a hard kill[like pressing the shutdown button in windows] if we close the session with clicking on the cross mark.
# 9  
Old 09-09-2014
Quote:
The screen vanished after the exit statement
This sounds like the "exit" is being interpreted by the terminal emulator not the Linux O/S. You should be able to issue an "exit" command to Linux and it will log you out and then give you a login prompt.

This should be separate from the commands given to the terminal emulator.

As per my post#4 I reckon failure to logout of Linux is leaving the process running.
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