Many C and C++ run-time library functions have a return value associated with them for error-checking purposes. For example, the _Rfeov() function returns 1 if the file has moved from one volume to the next. The fopen() function returns NULL if a file is not opened successfully. ILE C/C++ Run-Time Library Functions contains information about the ILE C/C++ function return values.
(C) Copyright IBM Corporation 1992, 2005. All Rights Reserved.