lib/charset: add u16_strlcat() function
Provide u16 string version of strlcat().
Signed-off-by: Masahisa Kojima <masahisa.kojima@linaro.org>
Reviewed-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
diff --git a/include/charset.h b/include/charset.h
index 38908e0..20abfbe 100644
--- a/include/charset.h
+++ b/include/charset.h
@@ -262,6 +262,20 @@
u16 *u16_strdup(const void *src);
/**
+ * u16_strlcat() - Append a length-limited, %NUL-terminated string to another
+ *
+ * Append the source string @src to the destination string @dest, overwriting
+ * null word at the end of @dest adding a terminating null word.
+ *
+ * @dest: zero terminated u16 destination string
+ * @src: zero terminated u16 source string
+ * @count: size of buffer in u16 words including taling 0x0000
+ * Return: required size including trailing 0x0000 in u16 words
+ * If return value >= count, truncation occurred.
+ */
+size_t u16_strlcat(u16 *dest, const u16 *src, size_t size);
+
+/**
* utf16_to_utf8() - Convert an utf16 string to utf8
*
* Converts 'size' characters of the utf16 string 'src' to utf8
diff --git a/lib/charset.c b/lib/charset.c
index de201cf..bece498 100644
--- a/lib/charset.c
+++ b/lib/charset.c
@@ -416,6 +416,22 @@
return new;
}
+size_t u16_strlcat(u16 *dest, const u16 *src, size_t count)
+{
+ size_t destlen = u16_strlen(dest);
+ size_t srclen = u16_strlen(src);
+ size_t ret = destlen + srclen + 1;
+
+ if (destlen >= count)
+ return ret;
+ if (ret > count)
+ srclen -= ret - count;
+ memcpy(&dest[destlen], src, 2 * srclen);
+ dest[destlen + srclen] = 0x0000;
+
+ return ret;
+}
+
/* Convert UTF-16 to UTF-8. */
uint8_t *utf16_to_utf8(uint8_t *dest, const uint16_t *src, size_t size)
{