This post describes how to modify the windows setup so double clicking on a .fmu file opens it in Windows explorer as if it were a zip file. This post is based on ‘How to register a new zip file extension on windows 10‘ with minor modifications to work with the .fmu file. This will require the user to have the rights to modify the PC registry.
What is a fmu file?
When a model is exported from Dymola using the FMI export option (i.e. Ctrl+F9) a Functional Mock-up Unit file is created. This is a file with a .fmu extension that adheres to the FMI standard. This .fmu is actually a .zip file with a format specified by the FMI standard. It can be useful to open these .fmu archives to examine the files within.
Modify the .fmu extension to open it as if it were a zip file
This can be done by editing the registry as described here with minor modifications to make it applicable for the .fmu extension. This is the exact process I followed:
1. Create a .reg file with this contents, using Notepad:
Windows Registry Editor Version 5.00
[HKEY_CLASSES_ROOT\.fmu]
@="CompressedFolder"
"Content Type"="application/x-zip-compressed"
"DontCompressInPackage"=""
"PerceivedType"="compressed"
[HKEY_CLASSES_ROOT\.fmu\OpenWithProgids]
"CompressedFolder"=""
[HKEY_CLASSES_ROOT\.fmu\PersistentHandler]
@="{098f2470-bae0-11cd-b579-08002b30bfeb}"2. Open registry editor, by typing regedit in the taskbar
a. Backup the registry, as described here.
b. Import the .reg file created in 1 (i.e. File>Import)
Now when a .fmu file is viewed in Windows Explorer you should see that the extension looks like that of a .zip file. As in the image below:
When this file is double clicked it is opened as if it were a zip file.
Written by: Garron Fish – Chief Engineer