# Background running of Julia on ubuntu

**URL:** <https://discourse.julialang.org/t/background-running-of-julia-on-ubuntu/38925>\
**Category:** General Usage\
**Tags:** question\
**Created:** [May 7, 2020, 2:07am UTC](https://discourse.julialang.org/t/background-running-of-julia-on-ubuntu/38925 "2020-05-07T02:07:43Z")\
**Posts on this page:** 18\
**Page:** 1

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**Author:** ![Jing\_Zhang](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/jing_zhang/32/13737_2.png) [@Jing\_Zhang](https://discourse.julialang.org/u/Jing_Zhang)\
**Post date:** [May 7, 2020, 2:07am UTC](https://discourse.julialang.org/t/background-running-of-julia-on-ubuntu/38925/1 "2020-05-07T02:07:43Z")

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Dear Julia users,

I am on a ubuntu machine. I want to run my Julia codes “main.jl” in background. What commend to realize this? Something like “nohup Julia command main.jl &”?

Thanks a lot!

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**Author:** ![PetrKryslUCSD](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/petrkryslucsd/32/215825_2.png) [@PetrKryslUCSD](https://discourse.julialang.org/u/PetrKryslUCSD)\
**Post date:** [May 7, 2020, 2:09am UTC](https://discourse.julialang.org/t/background-running-of-julia-on-ubuntu/38925/2 "2020-05-07T02:09:10Z")

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That is how I do it.

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**Author:** ![Jing\_Zhang](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/jing_zhang/32/13737_2.png) [@Jing\_Zhang](https://discourse.julialang.org/u/Jing_Zhang)\
**Post date:** [May 7, 2020, 3:14am UTC](https://discourse.julialang.org/t/background-running-of-julia-on-ubuntu/38925/3 "2020-05-07T03:14:03Z")

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I got this error as below

nohup: ignoring input and appending output to ‘nohup.out’  
nohup: failed to run command ‘Julia’: No such file or directory

[1]+ Exit 127 nohup Julia CMD main\_script.jl

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<div class="post-metadata">

**Author:** ![PetrKryslUCSD](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/petrkryslucsd/32/215825_2.png) [@PetrKryslUCSD](https://discourse.julialang.org/u/PetrKryslUCSD)\
**Post date:** [May 7, 2020, 3:15am UTC](https://discourse.julialang.org/t/background-running-of-julia-on-ubuntu/38925/4 "2020-05-07T03:15:08Z")

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julia is lowercase, at least on my system.

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<div class="post-metadata">

**Author:** ![Jing\_Zhang](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/jing_zhang/32/13737_2.png) [@Jing\_Zhang](https://discourse.julialang.org/u/Jing_Zhang)\
**Post date:** [May 7, 2020, 3:16am UTC](https://discourse.julialang.org/t/background-running-of-julia-on-ubuntu/38925/5 "2020-05-07T03:16:54Z")

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I tried both upper case Julia and lower case julia. Same error message.

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<div class="post-metadata">

**Author:** ![Jing\_Zhang](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/jing_zhang/32/13737_2.png) [@Jing\_Zhang](https://discourse.julialang.org/u/Jing_Zhang)\
**Post date:** [May 7, 2020, 3:22am UTC](https://discourse.julialang.org/t/background-running-of-julia-on-ubuntu/38925/6 "2020-05-07T03:22:50Z")

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“Julia main\_script.jl &” is fine. But the error message shows up after adding “nohup”

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<div class="post-metadata">

**Author:** ![PetrKryslUCSD](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/petrkryslucsd/32/215825_2.png) [@PetrKryslUCSD](https://discourse.julialang.org/u/PetrKryslUCSD)\
**Post date:** [May 7, 2020, 3:37am UTC](https://discourse.julialang.org/t/background-running-of-julia-on-ubuntu/38925/7 "2020-05-07T03:37:00Z")

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```julia
pkrysl@Hogwarts:~$ cat wher.jl
println("Here: $(pwd())")
exit()
pkrysl@Hogwarts:~$ nohup julia-3e47047021/bin/julia wher.jl &
[1] 14324
pkrysl@Hogwarts:~$ nohup: ignoring input and appending output to 'nohup.out'
cat nohup.out
Here: /home/pkrysl
[1]+ Done nohup julia-3e47047021/bin/julia wher.jl
pkrysl@Hogwarts:~$

```

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<div class="post-metadata">

**Author:** ![Jing\_Zhang](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/jing_zhang/32/13737_2.png) [@Jing\_Zhang](https://discourse.julialang.org/u/Jing_Zhang)\
**Post date:** [May 7, 2020, 3:41am UTC](https://discourse.julialang.org/t/background-running-of-julia-on-ubuntu/38925/8 "2020-05-07T03:41:39Z")

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The only difference I see is “julia-3e47047021/bin/julia” versus “julia”. So what is this piece of information “-3e47047021?” Thanks a lot.

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<div class="post-metadata">

**Author:** ![Jing\_Zhang](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/jing_zhang/32/13737_2.png) [@Jing\_Zhang](https://discourse.julialang.org/u/Jing_Zhang)\
**Post date:** [May 7, 2020, 3:45am UTC](https://discourse.julialang.org/t/background-running-of-julia-on-ubuntu/38925/9 "2020-05-07T03:45:38Z")

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I meant I don’t know how to specify this part “julia-3e47047021/bin/julia” for my ubuntu machine.

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**Author:** ![PetrKryslUCSD](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/petrkryslucsd/32/215825_2.png) [@PetrKryslUCSD](https://discourse.julialang.org/u/PetrKryslUCSD)\
**Post date:** [May 7, 2020, 3:53am UTC](https://discourse.julialang.org/t/background-running-of-julia-on-ubuntu/38925/10 "2020-05-07T03:53:52Z")

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Please do `which julia`. That will tell you where it is.

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<div class="post-metadata">

**Author:** ![PetrKryslUCSD](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/petrkryslucsd/32/215825_2.png) [@PetrKryslUCSD](https://discourse.julialang.org/u/PetrKryslUCSD)\
**Post date:** [May 7, 2020, 4:00am UTC](https://discourse.julialang.org/t/background-running-of-julia-on-ubuntu/38925/11 "2020-05-07T04:00:05Z")

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About the name of the folder: I just never bothered to rename the nightly Julia folder. It is called `julia-3e47047021`.

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<div class="post-metadata">

**Author:** ![Jing\_Zhang](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/jing_zhang/32/13737_2.png) [@Jing\_Zhang](https://discourse.julialang.org/u/Jing_Zhang)\
**Post date:** [May 7, 2020, 4:48am UTC](https://discourse.julialang.org/t/background-running-of-julia-on-ubuntu/38925/12 "2020-05-07T04:48:49Z")

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Ok. Thank you, Petr! With Julia’s full path, it works. I have also created an alias for the Julia path. So “nohup julia .jl &” also works now. 🙂

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**Author:** ![johnh](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/johnh/32/3615_2.png) [@johnh](https://discourse.julialang.org/u/johnh)\
**Post date:** [May 7, 2020, 4:58am UTC](https://discourse.julialang.org/t/background-running-of-julia-on-ubuntu/38925/13 "2020-05-07T04:58:32Z")

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I would install ‘screen’ then start a screen session in a terminal.

screen -S background-julia  
julia wher.jl  
Ctrl-a then D will detach the terminal and leave the process running in the bacground  
screen -r in a different terminal or the same terminal will reconnect you

When working on a remote server screen is invaluable

> **[How To Use Linux Screen](https://linuxize.com/post/how-to-use-linux-screen/)**
>
> Screen or GNU Screen, is a terminal multiplexer. In other words, it means that you can a start a screen session and then open any number of windows (virtual terminals) inside that session.

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<div class="post-metadata">

**Author:** ![Tamas\_Papp](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/tamas_papp/32/25949_2.png) [@Tamas\_Papp](https://discourse.julialang.org/u/Tamas_Papp)\
**Post date:** [May 7, 2020, 3:31pm UTC](https://discourse.julialang.org/t/background-running-of-julia-on-ubuntu/38925/14 "2020-05-07T15:31:41Z")

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I would also recommend tmux in place of nohup/screen.

[https://github.com/tmux/tmux/wiki](https://github.com/tmux/tmux/wiki)

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<div class="post-metadata">

**Author:** ![Jing\_Zhang](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/jing_zhang/32/13737_2.png) [@Jing\_Zhang](https://discourse.julialang.org/u/Jing_Zhang)\
**Post date:** [May 7, 2020, 6:11pm UTC](https://discourse.julialang.org/t/background-running-of-julia-on-ubuntu/38925/15 "2020-05-07T18:11:14Z")

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What is the advantage of screen comparing to nohup?

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<div class="post-metadata">

**Author:** ![Jing\_Zhang](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/jing_zhang/32/13737_2.png) [@Jing\_Zhang](https://discourse.julialang.org/u/Jing_Zhang)\
**Post date:** [May 7, 2020, 6:12pm UTC](https://discourse.julialang.org/t/background-running-of-julia-on-ubuntu/38925/16 "2020-05-07T18:12:08Z")

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I heard tmux is comparable to screen. Any particular reason on recommending tmux in place of nohup/screen?

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<div class="post-metadata">

**Author:** ![Jing\_Zhang](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/jing_zhang/32/13737_2.png) [@Jing\_Zhang](https://discourse.julialang.org/u/Jing_Zhang)\
**Post date:** [May 7, 2020, 7:02pm UTC](https://discourse.julialang.org/t/background-running-of-julia-on-ubuntu/38925/17 "2020-05-07T19:02:12Z")

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Just tried screen - nice tool! Thanks a lot.

I have two question which are not included in the tutorial you recommended - appreciate your help in advance.

1. I think I accidentally opened multiple screens now; see below. How to kill the ones I don’t need.

**screen -r**

**There are several suitable screens on:**

**10353.background-julia (05/07/2020 06:29:12 PM) (Attached)**

**10243.background-julia (05/07/2020 06:21:49 PM) (Detached)**

**10143.background-julia (05/07/2020 05:52:12 PM) (Attached)**

**10073.session\_name (05/07/2020 05:36:10 PM) (Attached)**

**10061.session\_name (05/07/2020 05:36:05 PM) (Attached)**

**10046.pts-1.ip-10-0-8-77 (05/07/2020 05:34:05 PM) (Detached)**

1. What are the differences between these Attached and Detached? I can only see my ubuntu in my terminal. I can open any screen with screen -r + id

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<div class="post-metadata">

**Author:** ![danielw2904](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/danielw2904/32/10890_2.png) [@danielw2904](https://discourse.julialang.org/u/danielw2904)\
**Post date:** [May 7, 2020, 7:53pm UTC](https://discourse.julialang.org/t/background-running-of-julia-on-ubuntu/38925/18 "2020-05-07T19:53:54Z")

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If it’s just a single process you want to run [dtach](http://dtach.sourceforge.net/) also works great