WCSRTOMBS(3) BSD Library Functions Manual WCSRTOMBS(3)NAMEwcsrtombs — converts a wide character string to a multibyte character
string (restartable)
LIBRARY
Standard C Library (libc, -lc)
SYNOPSIS
#include <stdlib.h>
size_t
wcsrtombs(const char * restrict s, const wchar_t ** restrict pwcs,
size_t n, mbstate_t * restrict ps);
DESCRIPTION
The wcsrtombs() converts the null-terminated wide character string indi‐
rectly pointed to by pwcs to the corresponding multibyte character
string, and stores it in the array pointed to by s. The conversion stops
due to the following reasons:
· The conversion reaches a null wide character. In this case, the null
wide character is also converted.
· The wcsrtombs() has already stored n bytes in the array pointed to by
s.
· The conversion encounters an invalid character.
Each character will be converted as if wcrtomb(3) is continuously called,
except the internal state of wcrtomb(3) will not be affected.
After conversion, if s is not a NULL pointer, the pointer object pointed
to by pwcs is a NULL pointer (if the conversion is stopped due to reach‐
ing a null wide character) or the first byte of the character just after
the last character converted.
If s is not a NULL pointer and the conversion is stopped due to reaching
a null wide character, wcsrtombs() places the state object pointed to by
ps to an initial state after the conversion is taken place.
The behaviour of wcsrtombs() is affected by the LC_CTYPE category of the
current locale.
These are the special cases:
s == NULL wcsrtombs() returns the number of bytes to store the whole
multibyte character string corresponding to the wide char‐
acter string pointed to by pwcs, not including the termi‐
nating null byte. In this case, n is ignored.
pwcs == NULL || *pwcs == NULL
Undefined (may cause the program to crash).
ps == NULL wcsrtombs() 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 wcsrtombs(), which
is initialized at startup time of the program.
RETURN VALUESwcsrtombs() returns:
0 or positive
Number of bytes stored in the array pointed to by s, except
for a null byte. 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 null-terminated.
(size_t)-1 pwcs points to a string containing an invalid wide charac‐
ter. The wcsrtombs() also sets errno to indicate the
error.
ERRORSwcsrtombs() may cause an error in the following case:
[EILSEQ] pwcs points to a string containing an invalid wide
character.
SEE ALSOsetlocale(3), wcrtomb(3), wcstombs(3)STANDARDS
The wcsrtombs() function conforms to ANSI X3.159-1989 (“ANSI C89”). The
restrict qualifier is added at ISO/IEC 9899:1999 (“ISO C99”).
BSD February 4, 2002 BSD
