putwc(3)

putwc3

Write a wide character to a file stream

Part of fputwc(3).

Usage

#include <stdio.h>
#include <wchar.h>

wint_t fputwc(wchar_t wc, FILE *stream); wint_t putwc(wchar_t wc, FILE *stream);

Library

Standard C library (libc, -lc)

Overview

The fputwc() function is the wide-character equivalent of the fputc(3) function. It writes the wide character wc to stream. If ferror(stream) becomes true, it returns WEOF. If a wide-character conversion error occurs, it sets errno to EILSEQ and returns WEOF. Otherwise, it returns wc.

The putwc() function or macro functions identically to fputwc(). It may be implemented as a macro, and may evaluate its argument more than once. There is no reason ever to use it.

For nonlocking counterparts, see unlocked_stdio(3).

Return value

On success, fputwc() function returns wc. Otherwise, WEOF is returned, and errno is set to indicate the error.

Errors

Apart from the usual ones, there is

EILSEQ

Conversion of wc to the stream's encoding fails.

Attributes

For an explanation of the terms used in this section, see attributes(7).

InterfaceAttributeValue
fputwc(), putwc()Thread safetyMT-Safe

Notes

The behavior of fputwc() depends on the LC_CTYPE category of the current locale.

In the absence of additional information passed to the fopen(3) call, it is reasonable to expect that fputwc() will actually write the multibyte sequence corresponding to the wide character wc.

Releases

14 releases since Debian 2.2 (Potato); the text changed 13 times.

  1. 2.2
  2. 3.0
  3. 3.1
  4. 4.0
  5. 5.0
  6. 6.0
  7. 7
  8. 8
  9. 9
  10. 10
  11. 11
  12. 12
  13. 13
  14. Arch

Standards

C11, POSIX.1-2008.

History

C99, POSIX.1-2001.

From man-pages 6.19-1 in Arch Linux 2026-11-01. Parsed by carta from the page's man source.