Adding a usage message when using a QNX C/C++ Project

To add a usage message to your application when using a QNX C/C++ Project:

In the Project Explorer view, open your project's common.mk file. This file specifies common options used for building all of your active variants.
Locate the USEFILE entry.
If your usage message is in app_name.use, where app_name is your executable name, add a # character at the start of the USEFILE line. This lets the recursive Makefile system automatically pick up your usage message.
If your usage message is in a file with a different name, or you want to explicitly specify your usage message's file name, change the USAGE line as follows:
```
USAGE=$(PROJECT_ROOT)/
```
usage_message.use
where usage_message.use is the name of the file containing your usage message. This also assumes that your usage message file is in the root of the project directory. If the usage message file is located in another directory, include it instead of $(PROJECT_ROOT).
Build your project as usual to include the usage message.