FPUTWC(3C) Standard C Library Functions FPUTWC(3C)
NAME
fputwc, putwc, putwchar - put wide-character code on a stream
SYNOPSIS
#include <stdio.h>
#include <wchar.h>
wint_t fputwc(
wchar_t wc,
FILE*stream);
wint_t putwc(
wchar_t wc,
FILE*stream);
#include <wchar.h>
wint_t putwchar(
wchar_t wc);
DESCRIPTION
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
abort(3C).
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.
RETURN VALUES
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 error.
ERRORS
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:
EAGAIN The
O_NONBLOCK flag is set for the file descriptor underlying
stream and the process 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 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.
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 process is neither
ignoring nor blocking
SIGTTOU, and the process group of the
process is orphaned.
stream was created by
open_wmemstream(3C) and a wide-character or byte sequence buffered is invalid in
the current locale.
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 will also be sent
to the calling thread.
The
fputwc(),
putwc(), and
putwchar() functions may fail if:
ENOMEM Insufficient storage space is available.
ENXIO A request was made of a non-existent device, or the request was
outside the capabilities of the device.
EILSEQ The wide-character code
wc does not correspond to a valid
character.
USAGE
Functions exist for the
putwc() and
putwchar() macros. To get the
function form, the macro name must be undefined (for example,
#undef putc).
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.
ATTRIBUTES
See
attributes(7) for descriptions of the following attributes:
+--------------------+-----------------+
|ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+--------------------+-----------------+
|Interface Stability | Standard |
+--------------------+-----------------+
|MT-Level | MT-Safe |
+--------------------+-----------------+
SEE ALSO
exit(2),
ulimit(2),
abort(3C),
fclose(3C),
ferror(3C),
fflush(3C),
fopen(3C),
setbuf(3C),
attributes(7),
standards(7) March 25, 2020
FPUTWC(3C)