make commands keep running after leaving a terminal session or ssh session

Danny3031 · 01-27-2012, 12:03 AM

I am trying to write a c++ code where i can run 3 parallel jobs via multithreading and want them to be alive even if i kill the terminal..But when ever i kill the terminal,the job also gets killed.Can i know how to do so?
Thanks in advance.

ukiuki · 01-27-2012, 12:26 AM

Use the & after the program command.
example:

Code:

$conky &

that should send the program to background.

Regards

paulsm4 · 01-27-2012, 12:28 AM

Hi -

To run a program in the background so you can exit the terminal, use "nohup":

Code:

nohup myprog &

Danny3031 · 01-27-2012, 12:31 AM

Yeah i know about the & operator but even if i am using it my code is not working.If i kill the terminal,my application also exits.
Lets say m trying to launch xlogo.so even if am using command : xlogo &. Then if i terminate the execution, xlogo goes in background.thats ok.but if i kill my terminal,then the xlogo is also killed but i want it to be alive.. So is there any way out so that i can keep my xlogo thing alive??

Danny3031 · 01-27-2012, 12:34 AM

Yeah am trying to use nohup only.
I am using it lyk nohup xlogo & but killing the terminal also kills the xlogo..

pyroscope · 01-27-2012, 12:54 AM

You have to use a daemonization double-fork WITHIN the application.

This is an example: https://github.com/jgshort/Narcissis...c_daemonizer.c

Use Google to find LOTS of similar snippets.

Danny3031 · 01-27-2012, 01:02 AM

It was way too complicated for me to understand. Can you explain me out in simple code example?
Or else i might show you my code over here.You check it and tell me where i m committing a mistake.

Danny3031 · 01-27-2012, 01:16 AM

Can somebody please reply to my question??

Danny3031 · 01-27-2012, 01:19 AM

I am not able to continue running xlogo if i kill my terminal.Can anybody please tell me what am i missing in my code?

Danny3031 · 01-27-2012, 02:52 AM

is there nobody who can help me over this??

Danny3031 · 01-27-2012, 03:12 AM

?????

dwhitney67 · 01-27-2012, 06:01 AM

Quote:

Originally Posted by Danny3031

Yeah am trying to use nohup only.
I am using it lyk nohup xlogo & but killing the terminal also kills the xlogo..

How are you "killing" the terminal?

If I run xlogo in the background, from a terminal, and exit the terminal gracefully (ie. exit or ctrl-d), then it keeps running.

If I kill the terminal using the X widget, then xlogo exits too. However, if I run xlogo using nohup, then it keeps running.

The title of your post indicated that you may also want to run xlogo via an SSH session, and I presume to keep it running even after the session has terminated. I do not believe this is possible, since it is SSH that is managing the port-forwarding of data, not the X11 server.

P.S. A little advice... when asking for help on this forum, continually requesting immediate help may actually dissuade other members from helping you. Always be patient. Sometimes it may take a day for someone to respond to your query.

firstfire · 01-27-2012, 07:51 AM

Hi.

If I understand your problem correctly, you may be interested in screen and/or tmux.

theNbomr · 01-27-2012, 10:36 AM

Quote:

Originally Posted by Danny3031

It was way too complicated for me to understand. Can you explain me out in simple code example?
Or else i might show you my code over here.You check it and tell me where i m committing a mistake.

You posted back only 8 minutes after the reply to your question. How much can you possibly have tried in such a brief time? You do have to put in a little effort.
--- rod.

War3zWad|0 · 01-28-2012, 02:53 AM

I would have to agree with firstfire in regards to your question. I use screen every day at work to run multiple tasks and when I exit the machine after detaching the screen session the task continues to run until completion.

and example:

Code:

[warezwaldo@m0b1l3 ~]$ screen
[warezwaldo@m0b1l3 ~]$ top -cd1
top - 02:47:55 up 2 days, 14:43,  4 users,  load average: 0.19, 0.15, 0.06
Tasks: 171 total,   1 running, 170 sleeping,   0 stopped,   0 zombie
Cpu(s):  2.9%us,  2.4%sy,  0.0%ni, 49.8%id, 44.4%wa,  0.5%hi,  0.0%si,  0.0%st
Mem:   2804540k total,  1864472k used,   940068k free,   721824k buffers
Swap:  4996208k total,        0k used,  4996208k free,   739076k cached

  PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND                                                                                        
30686 warezwal  20   0  396m  90m  32m S    6  3.3   0:24.16 /usr/lib/firefox/firefox-bin http://www.linuxquestions.org/questions/showthread.php?threadid=925
 1971 root      20   0 76420  57m  12m S    1  2.1  19:45.02 /usr/bin/Xorg -br :0 vt7 -nolisten tcp -auth /var/lib/xdm/authdir/authfiles/A:0-L1bGYa          
 8243 warezwal  20   0  311m  65m  29m S    1  2.4   5:05.16 kwin -session 101bf13f16c11b000131344581900000112470000_1327481044_934435                       
30799 warezwal  20   0  133m  44m  19m S    1  1.6   0:00.48 kdeinit4: konsole [kdeinit]                                                                     
30822 warezwal  20   0  2504  988  732 R    1  0.0   0:00.02 top -cd1                                                                                        
    1 root      20   0  2196  720  612 S    0  0.0   0:02.38 init [5]                                                                                        
    2 root      20   0     0    0    0 S    0  0.0   0:00.00 [kthreadd]                                                                                      
    3 root      RT   0     0    0    0 S    0  0.0   0:00.02 [migration/0]                                                                                   
    4 root      20   0     0    0    0 S    0  0.0   0:01.54 [ksoftirqd/0]                                                                                   
    5 root      RT   0     0    0    0 S    0  0.0   0:00.00 [watchdog/0]                                                                                    
    6 root      RT   0     0    0    0 S    0  0.0   0:00.02 [migration/1]                                                                                   
    7 root      20   0     0    0    0 S    0  0.0   0:10.36 [ksoftirqd/1]                                                                                   
    8 root      RT   0     0    0    0 S    0  0.0   0:00.00 [watchdog/1]                                                                                    
    9 root      20   0     0    0    0 S    0  0.0   0:06.95 [events/0]                                                                                      
   10 root      20   0     0    0    0 S    0  0.0   0:21.28 [events/1]                                                                                      
   11 root      20   0     0    0    0 S    0  0.0   0:00.00 [netns]                                                                                         
   12 root      20   0     0    0    0 S    0  0.0   0:00.00 [async/mgr]                                                                                     
   13 root      20   0     0    0    0 S    0  0.0   0:00.00 [pm]                                                                                            
   14 root      20   0     0    0    0 S    0  0.0   0:00.16 [sync_supers]                                                                                   
   15 root      20   0     0    0    0 S    0  0.0   0:00.25 [bdi-default]                                                                                   
[detached]

[warezwaldo@m0b1l3 ~]$ screen -ls
There is a screen on:
        30812.pts-1.m0b1l3      (Detached)
1 Socket in /var/run/uscreens/S-warezwaldo.

To exit screen use the following key sequence: CNTL+A+D then to return to your screen session (if only 1) use screen -x you will see that the task continues to run even if you disconnect from ssh. To exit screen just type exit.