Is argv[argc] equal to NULL Pointer [duplicate]
The Standard (C99 5.1.2.2.1p2) mandates that:
If they are declared, the parameters to the main function shall obey the following constraints:
— The value of argc shall be nonnegative.
— argv[argc] shall be a null pointer.
...
The rationale for this is to provide a redundant check for the end of the argument list, on the basis of common practice (ref: Rationale for the ANSI C programming language (1990), 2.1.2.2).