fwide (original) (raw)

[CX] The functionality described on this reference page is aligned with the ISO C standard. Any conflict between the requirements described here and the ISO C standard is unintentional. This volume of IEEE Std 1003.1-2001 defers to the ISO C standard.

The fwide() function shall determine the orientation of the stream pointed to by stream. If mode is greater than zero, the function first attempts to make the stream wide-oriented. If mode is less than zero, the function first attempts to make the stream byte-oriented. Otherwise, mode is zero and the function does not alter the orientation of the stream.

If the orientation of the stream has already been determined, fwide() shall not change it.

[CX] Since no return value is reserved to indicate an error, an application wishing to check for error situations should set_errno_ to 0, then call fwide(), then check errno, and if it is non-zero, assume an error has occurred.

The fwide() function shall return a value greater than zero if, after the call, the stream has wide-orientation, a value less than zero if the stream has byte-orientation, or zero if the stream has no orientation.

The following sections are informative.

End of informative text.