Is There Anything Special About Character Pointers?
Yes. When Pro*C/C++ binds an input or output host variable, it must know the length. When you use VARCHAR[n], or declare a host variable of type char[n], Pro*C/C++ knows the length from your declaration. But when you use a character pointer as a host variable, and use malloc() to define the buffer in your program, Pro*C/C++ has no way of knowing the length. On output you must not only allocate the buffer, but pad it out with some non-null characters, then null-terminate it. On input or output, Pro*C/C++ calls strlen() for the buffer to get the length. See “Pointer Variables “.
