The fputwc() function shall write 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 shall be 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().
The fputwc() function shall 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' file size limit.
The file is a regular file and an attempt was made to write
at or beyond the offset maximum associated with the corresponding
The wide-character code wc does not correspond to a
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 terminal, TOSTOP is set, the process is neither ignoring nor
blocking SIGTTOU, and the process group of the process is orphaned. This
error may also be returned under implementation-defined conditions.
There was no free space remaining on the device containing
An attempt is made to write to a pipe or FIFO that is not
open for reading by any process. A SIGPIPE signal shall also be sent to
The fputwc() function may fail if:
Insufficient storage space is available.
A request was made of a nonexistent device, or the request
was outside the capabilities of the device.
Portions of this text are reprinted and reproduced in electronic form from IEEE
Std 1003.1, 2003 Edition, Standard for Information Technology -- Portable
Operating System Interface (POSIX), The Open Group Base Specifications Issue
6, Copyright (C) 2001-2003 by the Institute of Electrical and Electronics
Engineers, Inc and The Open Group. In the event of any discrepancy between
this version and the original IEEE and The Open Group Standard, the original
IEEE and The Open Group Standard is the referee document. The original
Standard can be obtained online at http://www.opengroup.org/unix/online.html