Close the terminal but keep matlab running remotely

Hi, I have to run some programs remotely in a cluster.

The problem is the following, the programs run for two or three days (they are really heavy). I connect to the cluster and run the programs with the following command

matlab -nosplash -nodesktop -r script

the program runs properly, but if I close the terminal the program stops running, and if I disconnect from the network the program give me the following error: "broken pipe".

Is any way that I can run the program and I can disconnect or close the terminal and the program keep running?

Thank you very much

Answer 1

[Walter Roberson]

Investigate using "screen" or "vnc", if you want to be able to reconnect to the session.

If you want to be able to run the script "in batch", not needing to interact with it after it starts, then if it is a Unix-type system, consider using the system "batch" command, or else use

nohup matlab -nosplash -nodesktop -r "try; script; catch; end" < /dev/null > /dev/null 2> /dev/null

(bourne or ksh derivatives, might need a slightly different syntax on csh)

[Iván]

Hi Walter, thanks for your answer.

I don't need to interact with the script so I am going to try the nohup...

the part of the code

"try; script; catch; end"

I think I understand why you include it. but the part

< /dev/null > /dev/null 2> /dev/null

what is for?

I am going to try it tomorrow when I go back to the university.

[Walter Roberson]

In Unix-type systems using the most common command shells, a command line "<" followed by a path indicates the source of standard input (stdin). A command line ">" followed by a path indicates the destination of standard output (file id 1, stdout). A command line "2>" followed by a path indicates the destination of the error stream (file id 2, stderr). The path /dev/null on input is the completely empty file, so "< /dev/null" mean that there is no input. The path /dev/null on output means that the corresponding output is to be thrown away. Thus "< /dev/null > /dev/null 2> /dev/null" means that the program is get end-of-file immediately if it ever tries to use input, and anything it outputs on the standard output or standard error streams are to be thrown away.

If these parts of the command line were not provided, then when you used nohup, if the program ever needed input it would try to read from the terminal you issued the nohup command on; that would generate confusion at the very least, and probably an error (instead of a clean "there is no more input"). Likewise if the program ever needed to output then without those parts of the command line it would try to write to the terminal you started the nohup on, leading again to confusion or an error.

Note: I missed a character in the command. You should use

nohup matlab -nosplash -nodesktop -r "try; script; catch; end" < /dev/null > /dev/null 2> /dev/null &

Notice the "&" at the end of the line. That tells Unix-like systems to run as a separate process instead of waiting until the command finishes before allowing you to enter further commands.

[Iván]

I try it but I received the following error message:

Ambiguous output redirect

Any Idea?

Thank you very much

[Walter Roberson]

Which shell are you using?

[Iván]

Thank you very much for your answers Walter. I finally find the following code that worked for me:

unsetenv DISPLAY
nohup matlab -r mybgprocess -nodisplay -nosplash -nojvm -nodesktop > & ! matlab.out < mystdio.txt &

The file 'mybgprocess.m' contains the MATLAB commands that you want to run. It is important that this function has a QUIT or EXIT statement at the end so that the MATLAB process is closed after you script is done executing. The file 'mystdio.txt' can be an empty file, but it needs to exist. Without this file, the standard input of the MATLAB process would be empty, which would cause the MATLAB process to die. The file 'matlab.out' will store the output of the MATLAB Command Window to your commands.

Source:

http://www.mathworks.com/support/solutions/en/data/1-5P0HFE/?solution=1-5P0HFE