musl/src/multibyte/wcsnrtombs.c

53 lines
987 B
C

/*
* This code was written by Rich Felker in 2010; no copyright is claimed.
* This code is in the public domain. Attribution is appreciated but
* unnecessary.
*/
#include <stdlib.h>
#include <inttypes.h>
#include <wchar.h>
#include <errno.h>
#include "internal.h"
size_t wcsnrtombs(char *restrict dst, const wchar_t **restrict wcs, size_t wn, size_t n, mbstate_t *restrict st)
{
size_t l, cnt=0, n2;
char *s, buf[256];
const wchar_t *ws = *wcs;
if (!dst) s = buf, n = sizeof buf;
else s = dst;
while ( ws && n && ( (n2=wn)>=n || n2>32 ) ) {
if (n2>=n) n2=n;
wn -= n2;
l = wcsrtombs(s, &ws, n2, 0);
if (!(l+1)) {
cnt = l;
n = 0;
break;
}
if (s != buf) {
s += l;
n -= l;
}
cnt += l;
}
if (ws) while (n && wn) {
l = wcrtomb(s, *ws, 0);
if ((l+1)<=1) {
if (!l) ws = 0;
else cnt = l;
break;
}
ws++; wn--;
/* safe - this loop runs fewer than sizeof(buf) times */
s+=l; n-=l;
cnt++;
}
if (dst) *wcs = ws;
return cnt;
}