Command-Line Parsing and Initialization

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When you initialize the Ice runtime by calling initialize, you can pass the application's arguments to the initialization call.

In most languages, this argument vector is an in-out parameter. In C++, for example, argc is passed as a reference to an int:

C++

CommunicatorPtr initialize(int& argc, const char* argv[], ...other parameters...);

initialize parses the argument vector and initializes the new communicator's properties accordingly. It also removes all arguments that set Ice properties from the provided argument vector. For example, assume we invoke a C++ server as:

Shell

./server --myoption --Ice.Config=config -x a --Ice.Trace.Network=3 -y opt file

Initially, argc has the value 9, and argv has ten elements: the first nine elements contain the program name and the arguments, and the final element, argv[argc], contains a null pointer (as required by the C++ standard). When Ice::initialize returns, argc has the value 7 and argv contains the following elements:

./server
--myoption
-x
a
-y
opt
file
0             # Terminating null pointer

This means that you should initialize the Ice runtime before you parse the command line for your application-specific arguments. That way, the Ice-related options are stripped from the argument vector for you so you do not need to explicitly skip them.

initialize parses the arguments the same way in all languages, but only the overloads that update the argument array remove the options they consume. Other overloads leave the input unchanged or return the remaining arguments separately; see Communicator Initialization and Destruction.

See Also