Variable arguments are used by functions in the printf family (
fprintf, etc) and others to allow a function to be called with a different number of arguments each time, hence the name varargs.
To implement functions using the variable arguments feature, use
To call functions which take a variable number of arguments, ensure there is a full prototype with the trailing ellipsis in scope:
void err_exit(const char *format, ...); for example.
Most command line tools rely on arguments passed to the program upon its execution. Instead of prompting for input, these programs expect data or specific flags (which become booleans) to be set. This allows both the user and other programs to run the Python file passing it data as it starts. This section explains and demonstrates the implementation and usage of command line arguments in Python.