IsBadReadPtr

The IsBadReadPtr function verifies that the calling process has read access to the specified range of memory.

BOOL IsBadReadPtr(

CONST VOID *lp, // address of memory block
UINT ucb // size of block
);  

Parameters

lp

Points to the first byte of the memory block.

ucb

Specifies the size, in bytes, of the memory block. If this parameter is zero, the return value is zero.

Return Values

If the calling process has read access to all bytes in the specified memory range, the return value is zero.

If the calling process does not have read access to all bytes in the specified memory range, the return value is nonzero. To get extended error information, call GetLastError

Remarks

If the calling process has read access to some, but not all, of the bytes in the specified memory range, the return value is nonzero.

In a preemptive multitasking environment, it is possible for some other thread to change the process's access to the memory being tested. Even when the function indicates that the process has read access to the specified memory, you should use structured exception handling when attempting to access the memory. Use of structured exception handling enables the system to notify the process if an access violation exception occurs, giving the process an opportunity to handle the exception.

See Also

IsBadHugeReadPtr, IsBadHugeWritePtr, IsBadStringPtr, IsBadWritePtr