fputwc, putwc, putwchar - put wide-character code on a stream
wint_t fputwc(wchar_t wc, FILE*stream);
wint_t putwc(wchar_t wc, FILE*stream);
wint_t putwchar(wchar_t wc);
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.
The st_ctime and st_mtime fields of the file will be
marked for update between the successful execution of fputwc() and
the next successful completion of a call to fflush(3C) or
fclose(3C) on the same stream or a call to exit(2) or
The putwc() function is equivalent to fputwc(),
except that it is implemented as a macro.
The call putwchar(wc) is equivalent to
putwc(wc, stdout). The putwchar() routine
is implemented as a macro.
Upon successful completion, fputwc(), putwc(), and
putwchar() return wc. Otherwise, they return WEOF, the
error indicator for the stream is set, and errno is set to indicate the
The fputwc(), putwc(), and putwchar() functions will fail
if either the stream is unbuffered or data in the stream's buffer needs
to be written, and:
The O_NONBLOCK flag is set for the file descriptor
underlying stream and the process would be delayed in the write
The file descriptor underlying stream is not a
valid file descriptor open for writing.
An attempt was made to write to a file that exceeds the
maximum file size or the process's file size limit; or the file is a regular
file and an attempt was made to write at or beyond the offset maximum
associated with the corresponding stream.
The write operation was terminated due to the receipt of
a signal, and no data was transferred.
A physical I/O error has occurred, or the process is a
member of a background process group attempting to write to its controlling
is set, the process is neither ignoring nor blocking
, and the process group of the process is orphaned.
was created by open_wmemstream(3C)
and a wide-character
or byte sequence buffered is invalid in the current locale.
There was no free space remaining on the device
containing the file.
An attempt is made to write to a pipe or FIFO that
is not open for reading by any process. A SIGPIPE signal will also be
sent to the calling thread.
The fputwc(), putwc(), and putwchar()
functions may fail if:
Insufficient storage space is available.
A request was made of a non-existent device, or the
request was outside the capabilities of the device.
The wide-character code wc does not correspond to
a valid character.
Functions exist for the putwc() and putwchar() macros. To get the
function form, the macro name must be undefined (for example, #undef
When the macro form is used, putwc() evaluates the
stream argument more than once. In particular,
putwc(wc, *f++) does not work sensibly.
The fputwc() function should be used instead when evaluating the
stream argument has side effects.
See attributes(7) for descriptions of the following attributes: