WCRTOMB(3) | Library Functions Manual | WCRTOMB(3)

# NAME

`wcrtomb` — converts a wide character to a multibyte character (restartable)

# LIBRARY

Standard C Library (libc, -lc)

# SYNOPSIS

`#include <wchar.h>`

size_t
`wcrtomb`(char * restrict s, wchar_t wc, mbstate_t * restrict ps);

# DESCRIPTION

`wcrtomb`() converts the wide character given by wc to the corresponding multibyte character, and stores it in the array pointed to by s unless s is a null pointer. This function will modify the first at most `MB_CUR_MAX` bytes of the array pointed to by s.

The behaviour of `wcrtomb`() is affected by the `LC_CTYPE` category of the current locale.

These are the special cases:

wc == 0
  For state-dependent encodings, `wcrtomb`() stores a nul byte preceded by special byte sequence (if any) to return to an initial state in the array pointed to by s, and the state object pointed to by ps also returns to an initial state.
s == NULL
  `wcrtomb`() just places ps into an initial state. It is equivalent to the following call:

      wcrtomb(buf, L'\0', ps);

  Here, buf is a dummy buffer. In this case, wc is ignored.

ps == NULL
  `mbrtowc`() uses its own internal state object to keep the conversion state, instead of ps mentioned in this manual page.

  Calling any other functions in Standard C Library (libc, -lc) never changes the internal state of `mbrtowc`(), which is initialized at startup time of the program.

# RETURN VALUES

`wcrtomb`() returns:

positive
  The number of bytes (including any shift sequences) which are stored in the array.
(size_t)-1
  wc is not a valid wide character. In this case, `wcrtomb`() also sets errno to indicate the error.

# ERRORS

`wcrtomb`() may cause an error in the following case:

[`EILSEQ`]
  wc is not a valid wide character.
[`EINVAL`]
  ps points to an invalid or uninitialized mbstate_t object.

# SEE ALSO

setlocale(3), wctomb(3)

# STANDARDS

The `wcrtomb`() function conforms to ISO/IEC 9899/AMD1:1995 (“ISO C90, Amendment 1”). The restrict qualifier is added at ISO/IEC 9899:1999 (“ISO C99”).

February 4, 2002 | NetBSD 11.0