lib: charset: add u16_str<n>cmp()

u16 version of strcmp(): u16_strncmp() works like u16_strcmp() but only
at most n characters (in u16) are compared.
This function will be used in my UEFI secure boot patch.

Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Reviewed-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
This commit is contained in:
AKASHI Takahiro 2019-09-18 10:26:29 +09:00 committed by Heinrich Schuchardt
parent 5a24239c95
commit f8062c963a
2 changed files with 40 additions and 0 deletions

View File

@ -168,6 +168,21 @@ s32 utf_to_lower(const s32 code);
*/
s32 utf_to_upper(const s32 code);
/*
* u16_strncmp() - compare two u16 string
*
* @s1: first string to compare
* @s2: second string to compare
* @n: maximum number of u16 to compare
* Return: 0 if the first n u16 are the same in s1 and s2
* < 0 if the first different u16 in s1 is less than the
* corresponding u16 in s2
* > 0 if the first different u16 in s1 is greater than the
* corresponding u16 in s2
*/
int u16_strncmp(const u16 *s1, const u16 *s2, size_t n);
#define u16_strcmp(s1, s2) u16_strncmp((s1), (s2), SIZE_MAX)
/**
* u16_strlen - count non-zero words
*

View File

@ -335,6 +335,31 @@ s32 utf_to_upper(const s32 code)
return ret;
}
/*
* u16_strncmp() - compare two u16 string
*
* @s1: first string to compare
* @s2: second string to compare
* @n: maximum number of u16 to compare
* Return: 0 if the first n u16 are the same in s1 and s2
* < 0 if the first different u16 in s1 is less than the
* corresponding u16 in s2
* > 0 if the first different u16 in s1 is greater than the
* corresponding u16 in s2
*/
int u16_strncmp(const u16 *s1, const u16 *s2, size_t n)
{
int ret = 0;
for (; n; --n, ++s1, ++s2) {
ret = *s1 - *s2;
if (ret || !*s1)
break;
}
return ret;
}
size_t u16_strlen(const void *in)
{
const char *pos = in;