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PROLOG
This manual page is part of the POSIX Programmer's Manual. The Linux implementation of this interface
may differ (consult the corresponding Linux manual page for details of Linux behavior), or the interface
may not be implemented on Linux.
NAME
fputwc — put a wide-character code on a stream
SYNOPSIS
#include <stdio.h> #include <wchar.h> wint_t fputwc(wchar_t wc, FILE *stream);
DESCRIPTION
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
POSIX.1‐2017 defers to the ISO C standard.
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 last data modification and last file status change timestamps 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 not change the setting of errno if successful.
RETURN VALUE
Upon successful completion, fputwc() shall return wc. Otherwise, it shall return WEOF, the error
indicator for the stream shall be set, and errno shall be set to indicate the error.
ERRORS
The fputwc() function shall fail if either the stream is unbuffered or data in the stream's buffer needs
to be written, and:
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 or 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
associated with the corresponding stream.
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.
This error may also be returned under implementation-defined conditions.
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 shall also be sent to the thread.
The fputwc() function may fail if:
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.
The following sections are informative.
EXAMPLES
None.
APPLICATION USAGE
None.
RATIONALE
None.
FUTURE DIRECTIONS
None.
SEE ALSO
Section 2.5, Standard I/O Streams, ferror(), fopen(), setbuf(), ulimit()
The Base Definitions volume of POSIX.1‐2017, <stdio.h>, <wchar.h>
COPYRIGHT
Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1-2017, Standard
for Information Technology -- Portable Operating System Interface (POSIX), The Open Group Base
Specifications Issue 7, 2018 Edition, Copyright (C) 2018 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 .
Any typographical or formatting errors that appear in this page are most likely to have been introduced
during the conversion of the source files to man page format. To report such errors, see
https://www.kernel.org/doc/man-pages/reporting_bugs.html .