Allows table operator writers to access a specific input attribute value in the current row of a stream.
Returns an integer indicating TBLOP_SUCCESS, TBLOP_ERROR, or TBLOP_ABORT.
This function returns an error in the following cases:
- The handle is associated with an output stream.
- The stream number or index is out of bounds.
- The stream is not open.
- The stream is not set up to access attributes directly. To access attributes directly, open the stream with options TBLOP_NOOPTIONS.