Attach to Existing MATLAB Sessions

This example shows how to attach an engine program to a MATLAB^® session on a Windows^® platform that is already running.

MATLAB does not support connecting an engine program to an existing MATLAB session on the macOS and Linux^® platforms.

On a Windows platform, start MATLAB with -automation in the command line. When you call engOpen, it connects to this existing session. Call engOpen only once, because any engOpen calls now connect to this one MATLAB session.

The -automation option also causes the command window to be minimized. You must open it manually.

In MATLAB, capture the value returned by the command:

mlpath = fullfile(matlabroot,"bin","win64")

Shut down all MATLAB sessions.

From the Start button on the Windows menu bar, type run.

In the Run dialog box Open field, type the following command, replacing mlpath with the value from the path command:

mlpath\matlab.exe -automation

To start MATLAB, click OK.

In MATLAB, copy the engwindemo.c example to a writable folder.

copyfile(fullfile(matlabroot,"extern","examples","eng_mat","engwindemo.c"),".", "f")

Build the example.

mex -client engine engwindemo.c

Run the engwindemo program by typing at the MATLAB prompt:

!engwindemo

This command does not start another MATLAB session, but uses the MATLAB session that is already open.