Detect an error and raise flag in Python when running an Matlab script from Python-CodePudding

I have a Matlab script that I am running it from Python. I want to detect any error happening in my Matlab script and raise a flag in Python (e.g. e = "error message from Matlab" and print(e) or if error_in_matlab: e=1). Here is my simplified code to run my yyy.m matlab script:

import os
path_to_mfile = '/Users/folder/yyy'
matlabCommandStr = 'matlab -nodisplay -r "clear all; close all; run(\'{}\'); quit" '.format(path_to_mfile)

while True:
    try:
        os.system(matlabCommandStr)
    except Exception as e:
        print(e)
        error_flag = 1
        break

I know that if I use Matlab toolbox in Python, following code will work:

import matlab.engine
while True:
    try:
        eng = matlab.engine.start_matlab()
        ret = eng.yyy()
    except Exception as e:
        print(e)
        error_flag = 1
        break

But I need to work with the command line because of matlab.engine limitation and the toolbox that I am preparing is already complicated enough to change to matlab.engine, so I want to keep using os.system(matlabCommandStr). I'd appreciate if someone can help with this.

CodePudding user response：

Using the hint from @CrisLuengo's answer, I used -batch instead of -nodisplay -r and then when there is an error status = 256 and if no error happens then status = 0. I used this as a flag to detect errors. The following code helped me to solve this problem:

import os
path_to_mfile = '/Users/folder/yyy'
matlabCommandStr = 'matlab -batch "run(\'{}\'); quit" '.format(path_to_mfile)

while True:
    status = os.system(matlabCommandStr)
    if status == 256:
        error_flag = 1

I will integrate this into my multiprocess tool. If there were further problems, I'll update here.