WCSTOMBS(3) | Library Functions Manual | WCSTOMBS(3)

# NAME

`wcstombs` —
converts a wide-character string to a multibyte character string

# LIBRARY

Standard C Library (libc, -lc)

# SYNOPSIS

`#include <stdlib.h>`

size_t
`wcstombs`(char * restrict s, const wchar_t * restrict pwcs, size_t n);

# DESCRIPTION

`wcstombs`() converts the nul-terminated wide-character string pointed to by pwcs to the corresponding multibyte character string, and stores it in the array pointed to by s. This function may modify the first at most n bytes of the array pointed to by s. Each character will be converted as if wctomb(3) is continuously called, except the internal state of wctomb(3) will not be affected.

For state-dependent encoding, the `wcstombs`() implies the result multibyte character string pointed to by s always to begin with an initial state.

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

These are the special cases:

s == NULL
  The `wcstombs`() returns the number of bytes to store the whole multibyte character string corresponding to the wide-character string pointed to by pwcs. In this case, n is ignored.
pwcs == NULL
  Undefined (may cause the program to crash).

# RETURN VALUES

`wcstombs`() returns:

0 or positive
  Number of bytes stored in the array pointed to by s. There are no cases that the value returned is greater than n (unless s is a null pointer). If the return value is equal to n, the string pointed to by s will not be nul-terminated.
(size_t)-1
  pwcs points to a string containing an invalid wide character. `wcstombs`() also sets errno to indicate the error.

# ERRORS

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

[`EILSEQ`]
  pwcs points to a string containing an invalid wide character.

# SEE ALSO

mbstowcs(3), setlocale(3), wctomb(3)

# STANDARDS

The `wcstombs`() function conforms to ANSI X3.159-1989 (“ANSI C89”). The restrict qualifier is added at ISO/IEC 9899:1999 (“ISO C99”).

March 16, 2011 | NetBSD 9.2