From eca08ce94ceb72358c5fb00e82506c0f74e65e3f Mon Sep 17 00:00:00 2001 From: Masahisa Kojima Date: Thu, 28 Apr 2022 17:09:34 +0900 Subject: [PATCH] lib/charset: add u16_strlcat() function Provide u16 string version of strlcat(). Signed-off-by: Masahisa Kojima Reviewed-by: Heinrich Schuchardt --- include/charset.h | 14 ++++++++++++++ lib/charset.c | 16 ++++++++++++++++ 2 files changed, 30 insertions(+) diff --git a/include/charset.h b/include/charset.h index 38908e08f0..20abfbe752 100644 --- a/include/charset.h +++ b/include/charset.h @@ -261,6 +261,20 @@ u16 *u16_strcpy(u16 *dest, const u16 *src); */ 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 * diff --git a/lib/charset.c b/lib/charset.c index de201cf3b9..bece4985bf 100644 --- a/lib/charset.c +++ b/lib/charset.c @@ -416,6 +416,22 @@ u16 *u16_strdup(const void *src) 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) { -- 2.39.5