Portability Function: Returns the last error set.
The result type is INTEGER(4). The result is the integer corresponding to the last run-time error value that was set.
For example, if you use an ERR= specifier in an I/O statement, your program will not abort if an error occurs. GETLASTERROR provides a way to determine what the error condition was, with a better degree of certainty than just examining
errno. Your application can then take appropriate action based upon the error number.