scc

commit 1908a6ea5f748db20b6b2e9f2eda55ae40d0bd75
parent 1a210c4013e2c6f78fafacc3655b54640541e4a2
Author: Roberto E. Vargas Caballero <k0ga@shike2.com>
Date:   Wed,  9 Nov 2022 21:04:49 +0100

libc/wchar: Add wcsrtombs()

Diffstat:
M
src/libc/objs/common-objs.mk
 | 
1
+
M
src/libc/wchar/Makefile
 | 
1
+
A
src/libc/wchar/wcsrtombs.c
 | 
38
++++++++++++++++++++++++++++++++++++++

3 files changed, 40 insertions(+), 0 deletions(-)
diff --git a/src/libc/objs/common-objs.mk b/src/libc/objs/common-objs.mk
@@ -124,6 +124,7 @@ COMMON_OBJS =\
 	wchar/mbsrtowcs.$O\
 	wchar/wcrtomb.$O\
 	wchar/wcslen.$O\
+	wchar/wcsrtombs.$O\
 	wchar/wcwidth.$O\
 	wchar/putwc.$O\
 	wchar/_validutf8.$O\
diff --git a/src/libc/wchar/Makefile b/src/libc/wchar/Makefile
@@ -10,6 +10,7 @@ OBJS =\
 	mbsrtowcs.$O\
 	wcrtomb.$O\
 	wcslen.$O\
+	wcsrtombs.$O\
 	wcwidth.$O\
 	putwc.$O\
 	_validutf8.$O\
diff --git a/src/libc/wchar/wcsrtombs.c b/src/libc/wchar/wcsrtombs.c
@@ -0,0 +1,38 @@
+#include <string.h>
+#include <limits.h>
+#include <wchar.h>
+
+#undef wcsrtombs
+
+size_t
+wcsrtombs(char *restrict dest, const wchar_t **restrict src,
+          size_t len, mbstate_t *restrict ps)
+{
+	size_t cnt, n;
+	wchar_t wc;
+	char buf[MB_LEN_MAX];
+	static mbstate_t p;
+
+	if (!ps)
+		ps = &p;
+
+	for (n = 0; ; n += cnt) {
+		wc = **src;
+		cnt = wcrtomb(buf, wc, ps);
+		if (cnt == (size_t) -1)
+			return -1;
+
+		if (dest) {
+			if (n+cnt > len)
+				return n;
+			memcpy(dest+n, buf, cnt);
+		}
+		*src += 1;
+
+		if (wc == L'\0')
+			break;
+	}
+	*src = NULL;
+
+	return n;
+}