When writing a Language Environment-conforming AMODE 64 application, it is important to consider how parameters are passed to the application on invocation. The type of parameter list created by the operating system and passed to Language Environment when an application is run varies according to the operating system or subsystem used. Language Environment repackages the various formats so that what is actually passed to the main routine when it is invoked on most supported operating systems is a halfword prefixed character string. In C and C++, you can pass arguments to the main routine through argv and argc. If you set up your C or C++ main routine according to the rules of the language, you generally do not need to do anything special to receive parameters from the operating system. In this case, use the constructs provided by the C or C++ language. Refer to z/OS XL C/C++ Language Reference for more details.