1

This is quite an interesting thing I noticed, for instance:

  • I use Atom Editor and I call it via my Terminal using:

    $ atom

    and press Enter, which triggers the Editor and also make the terminal cursor point to the new line; making it (Terminal) free for further command line utilities.

  • However, when in use RhythmBox using rhythmbox as terminal command, it tends to work on the foreground (I guess) and keeps the terminal occupied till I close Rhythmbox or use CTRL+C.

I tried this with texmaker too and it performs similar thing as Rhythmbox. I know that & will take the process on the background but is there a logical explanation for some applications as mentioned here?

Any hacks or tips so that I can learn how to tweak things like this?

Note

I try using CTRL+Z on the above mentioned applications and the apps then gray out and become unresponsive and I have to force quit on them

Environment

  • Using Ubuntu 16.10

  • Gnome Terminal

  • echo $SHELL give /bin/bash

muru
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Shan-Desai
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    I believe their developers coded this behaviour ( free terminal) into them while others didn't – George Udosen Mar 17 '17 at 12:59
  • George is right. Not a setting. Not tweak-able. Requires a patch the source code. – user535733 Mar 17 '17 at 13:01
  • You can press Ctrl+Z to "free the terminal", but keep the program open. OR many other ways – M. Becerra Mar 17 '17 at 13:02
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    It behaves nasty when use CTRL+Z on both rhythmbox and texmaker @M.Becerra Both apps freeze and do not work. I have to forcefully kill them using their PID – Shan-Desai Mar 17 '17 at 13:06
  • @user535733 technically, program itself isn't tweakable unless you modify the source code, but there are Linux tools to detach a program from controlling terminal. See my answer – Sergiy Kolodyazhnyy Mar 17 '17 at 14:51
  • use Ctrl+Z and then the command bg. Ctrl+Z pauses the program,that is therefore unresponsive, bg sends the program to the background and it is responsive again. – jarleih Mar 17 '17 at 15:34

2 Answers2

3

As has been pointed out in the comments, such behavior is specific to each application. Applications written in C programming language, for example, can employ setsid call to disconnect from controlling terminal, although they require call to fork() syscall first. Python, also has os.setsid() and os.fork() functions; although it is possible to simply use os.fork() to create a child process and kill the parent.

Another very frequent technique that software authors use is launching applications via wrapper script, and calling a new process via nohup. That's exactly what atom does:

$ file $(which atom)
/usr/bin/atom: Bourne-Again shell script, ASCII text executable
$ grep 'nohup' $(which atom)                                                            
    nohup "$ATOM_PATH" --executed-from="$(pwd)" --pid=$$ "$@" > "$ATOM_HOME/nohup.out" 2>&1
      cat "$ATOM_HOME/nohup.out"

You can do so as well. For instance, the way I tend to launch programs and detach them from terminal is via a function, that launches desired program with nohup already appended to the command:

runstuff() {
    nohup "$@" >/dev/null 2>&1 & 
}

Once you define that in your .bashrc , you can launch firefox like so :

runstuff firefox

Another way, is via setsid command (which is named same as the C system call, but is actually a standalone binary):

setsid firefox
Community
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Sergiy Kolodyazhnyy
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1

If you use Ubuntu with X environemnt you can push Ctrl + F2 and then put the command you need (i.e. rythmbox). It won't have separate terminal where you can push ctrl+C.

You can also try to run nohup rythmbox &. It should run your player in backgroud and make it terminal-close-proof.

Kamil
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