AfxIsValidString 

BOOL AfxIsValidString( LPCSTR lpsz, int nLength = -1 );

Return Value

Nonzero if the specified pointer points to a string of the specified size; otherwise 0.

Parameters

lpsz

The pointer to test.

nLength

Specifies the length of the string to be tested, in bytes. A value of –1 indicates that the string will be null-terminated.

Remarks

Use this function to determine whether a pointer to a string is valid.

Example

// Create a character string which should be valid.
char str[12] = "hello world";

// Create a null pointer, which should be an invalid string.
char *null = (char *)0x0;

ASSERT(AfxIsValidString(str, 12));
ASSERT(!AfxIsValidString(null, 5));

See Also   AfxIsMemoryBlock, AfxIsValidAddress