wait for several system calls to finish
조회 수: 10 (최근 30일)
이전 댓글 표시
I am calling three external programs and can only continue in the matlab program after all programs are finished. Each of them work independently of each other and can start at the same time
[staus1,~] = system('cmd1 &');
[staus2,~] = system('cmd2 &');
[staus3,~] = system('cmd3 &');
% how to check if all of them are finished?
Using ampersand & symbol, I reached that they start nearly at the same time, but how can I check when they are all finished? In my case, the returned status variables can be zero (successful) or negative (not successful). Hence, checking status for any value does not help, I guess.
댓글 수: 0
채택된 답변
Walter Roberson
2024년 4월 20일
You have to use taskmgr (Windows) or ps (MacOS or Linux) to detect whether the processes are still alive.
Note: If you are using Windows then I recommend that you instead use System.Diagnostics.Process which is able to start processes independently, and allows their status to be checked.
댓글 수: 3
Walter Roberson
2024년 4월 21일
You could use
ps | grep matlab | tail
and parse out the process ID. Then you could start the new process, and then
ps -g PROCESS_ID_GOES_HERE
to get the process ID of the new process.
Then you could use the java watcher https://www.mathworks.com/matlabcentral/answers/398152-listening-to-the-creation-deletion-of-a-file-with-specific-name#answer_317920 on /proc/PROCESS_ID_OF_NEW_PROCESS watching for deletion
... something like that
추가 답변 (1개)
Mario Malic
2024년 4월 20일
Ampersand means that program will be started and MATLAB will not wait for it to be terminated and will continue to execute next lines of code.
What does it mean that they are finished? Does the program exits when it's done?
You can remove ampersand, then you have to close the program for MATLAB to execute next lines.
댓글 수: 8
Walter Roberson
2024년 4월 26일
I cannot think of any way to get the information about the process exit status.
Mario Malic
2024년 4월 27일
If I understood correctly, multistart does that already, it has multiple starting points. By running multistart in parallel, each of these runs may lead to the minimum that already has been found by some other multistart process.
If you are looking for a any (tedious) solution, you could write a file from your c++ code indicating the exit status and read it with MATLAB once process is deleted.
참고 항목
카테고리
Help Center 및 File Exchange에서 Get Started with MATLAB에 대해 자세히 알아보기
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!