OutputDebugString Checker can be used from the command line as well as with the GUI.
User interface
If command line arguments are detected the user interface is not displayed.
Error reporting
When running from the command line any errors are written to the output file specified on the command line.
Return code
The process return code is 0 for no function calls found.
If there are function calls found the return code is a positive integer describing the number of function calls found.