fputwc

fputwc is a function in the C standard library that writes a wide character to a file stream. It is declared in the header <wchar.h> and is the wide-character counterpart of fputc.

The function has the prototype: int fputwc(wchar_t wc, FILE *stream); It writes the wide character wc to the specified stream.

Return value and error handling: On success, fputwc returns the value written, promoted to int. If an error occurs, it returns WEOF and the stream’s error indicator is set.

Parameters and behavior: wc is the wide character to write, and stream is the FILE object to which the character will be written. The stream must be suitable for wide-oriented I/O; if the stream is not appropriate for wide-oriented operations, the behavior is implementation-defined or undefined.

Encoding and locale considerations: The actual bytes produced depend on the stream’s encoding and the current locale. If the wide character cannot be represented in the stream’s encoding, a conversion error may occur, resulting in a return value of WEOF and the stream error indicator being set.

Relation to other functions: fputwc is the wide-character counterpart to fputc, and is related to other wide-character I/O facilities such as fgetwc and putwc.

Example usage: A typical pattern is to open a file for writing with fopen, call fputwc with a wide character and the FILE*, check for WEOF to detect errors, and finally close the file with fclose.

Note: As with other I/O functions, proper error checking and handling of locale and encoding are important for portable use across platforms.