Implementation status: to be implemented


#include <stdio.h>

#include <wchar.h>

wint_t fputwc(wchar_t wc, FILE *stream);


The fputwc() function writes the character corresponding to the wide-character code wc to the output stream pointed to by stream, at the position indicated by the associated file-position indicator for the stream (if defined), and advances the indicator appropriately. If the file cannot support positioning requests, or if the stream was opened with append mode, the character is appended to the output stream. If an error occurs while writing the character, the shift state of the output file is left in an undefined state.


wc - a wide character to be written,
stream - the output stream.

The last data modification and last file status change timestamps of the file are marked for update between the successful execution of fputwc() and the next successful completion of a call to fflush() or fclose() on the same stream or a call to exit() or abort().

Return value

Upon successful completion, fputwc() returns wc.
Otherwise, it returns WEOF, sets an error indicator for the stream, and sets errno to indicate the error.


[EAGAIN] The O_NONBLOCK flag is set for the file descriptor underlying stream and the thread would be delayed in the write operation.
[EBADF] The file descriptor underlying stream is not a valid file descriptor open for writing.
[EFBIG] An attempt was made to write to a file that exceeds the maximum file size.
[EFBIG] An attempt was made to write to a file that exceeds the file size limit of the process.
[EFBIG] The file is a regular file and an attempt was made to write at or beyond the offset maximum.
[EILSEQ] The wide-character code wc does not correspond to a valid character.
[EINTR] The write operation was terminated due to the receipt of a signal, and no data was transferred.
[EIO] A physical I/O error has occurred, or the process is a member of a background process group attempting to write to its controlling terminal, TOSTOP is set, the calling thread is not blocking SIGTTOU, the process is not ignoring SIGTTOU, and the process group of the process is orphaned.
[ENOSPC] There was no free space remaining on the device containing the file.
[EPIPE] An attempt is made to write to a pipe or FIFO that is not open for reading by any process. A SIGPIPE signal is also sent to the thread.
[ENOMEM] Insufficient storage space is available.
[ENXIO] A request was made of a nonexistent device, or the request was outside the capabilities of the device.

Implementation tasks

  • Implement wchar.h file
  • Implement the fputwc() function