Attaching to an Existing MATLAB Session :: Calling MATLAB from C and Fortran Programs (External Interfaces)

External Interfaces

Attaching to an Existing MATLAB Session

You can make a MATLAB engine program attach to a MATLAB session that is already running by starting the MATLAB session with /Automation in the command line. When you make a call to engOpen, it will then connect to this existing session. You should only call engOpen once, as any engOpen calls will now connect to this one MATLAB session.

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

Note For more information on the /Automation command line argument, see Additional Automation Server Information. For information about the Component Object Model interfaces used by MATLAB, see Introducing MATLAB COM Integration.

For example:

Shut down any MATLAB sessions.
From the Start button on the Windows menu bar, click Run.
In the Open field, type

d:\matlab\bin\win32\matlab.exe /Automation

where d:\matlab\bin\win32 represents the path to the MATLAB executable.

Click OK. This starts MATLAB.
In MATLAB, change directories to $MATLAB/extern/examples/eng_mat, where $MATLAB is the MATLAB root directory.
Compile the engwindemo.c example.
Run the engwindemo program by typing at the MATLAB prompt

```
!engwindemo
```

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

Note On the UNIX platform, you cannot make a MATLAB engine program use a MATLAB session that is already running.

Calling MATLAB from a Fortran Application Compiling and Linking Engine Programs