busybox/libbb/unicode.c

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/* vi: set sw=4 ts=4: */
/*
* Unicode support routines.
*
* Copyright (C) 2008 Denys Vlasenko
*
* Licensed under GPL version 2, see file LICENSE in this tarball for details.
*/
#include "libbb.h"
# include "unicode.h"
size_t FAST_FUNC bb_mbstrlen(const char *string)
{
size_t width = mbstowcs(NULL, string, INT_MAX);
if (width == (size_t)-1L)
return strlen(string);
return width;
}
#if !ENABLE_LOCALE_SUPPORT
/* Crude "locale support" which knows only C and Unicode locales */
/* unicode_is_enabled:
* 0: not known yet,
* 1: not unicode (IOW: assuming one char == one byte)
* 2: unicode
*/
# if !ENABLE_FEATURE_CHECK_UNICODE_IN_ENV
# define unicode_is_enabled 2
# else
static smallint unicode_is_enabled;
void FAST_FUNC check_unicode_in_env(void)
{
char *lang;
if (unicode_is_enabled)
return;
unicode_is_enabled = 1;
lang = getenv("LANG");
if (!lang || !strstr(lang, ".utf8"))
return;
unicode_is_enabled = 2;
}
# endif
static size_t wcrtomb_internal(char *s, wchar_t wc)
{
int n;
uint32_t v = wc;
if (v <= 0x7f) {
*s = v;
return 1;
}
/* RFC 3629 says that Unicode ends at 10FFFF,
* but we cover entire 32 bits */
n = 2;
/* 4000000-FFFFFFFF -> 111111tt 10tttttt 10zzzzzz 10zzyyyy 10yyyyxx 10xxxxxx */
if (v >= 0x4000000) {
s[5] = (wc & 0x3f) | 0x80;
wc = (uint32_t)wc >> 6; /* ensuring that high bits are 0 */
n++;
}
/* 200000-3FFFFFF -> 111110tt 10zzzzzz 10zzyyyy 10yyyyxx 10xxxxxx */
if (v >= 0x200000) {
s[4] = (wc & 0x3f) | 0x80;
wc >>= 6;
n++;
}
/* 10000-1FFFFF -> 11110zzz 10zzyyyy 10yyyyxx 10xxxxxx */
if (v >= 0x10000) {
s[3] = (wc & 0x3f) | 0x80;
wc >>= 6;
n++;
}
/* 800-FFFF -> 1110yyyy 10yyyyxx 10xxxxxx */
if (v >= 0x800) {
s[2] = (wc & 0x3f) | 0x80;
wc >>= 6;
n++;
}
s[1] = (wc & 0x3f) | 0x80;
wc >>= 6;
s[0] = wc | (uint8_t)(0x3f00 >> n);
return n;
}
size_t FAST_FUNC wcrtomb(char *s, wchar_t wc, mbstate_t *ps UNUSED_PARAM)
{
if (unicode_is_enabled != 2) {
*s = wc;
return 1;
}
return wcrtomb_internal(s, wc);
}
size_t FAST_FUNC wcstombs(char *dest, const wchar_t *src, size_t n)
{
size_t org_n = n;
if (unicode_is_enabled != 2) {
while (n) {
wchar_t c = *src++;
*dest++ = c;
if (c == 0)
break;
n--;
}
return org_n - n;
}
while (n >= MB_CUR_MAX) {
wchar_t wc = *src++;
size_t len = wcrtomb_internal(dest, wc);
if (wc == L'\0')
return org_n - n;
dest += len;
n -= len;
}
while (n) {
char tbuf[MB_CUR_MAX];
wchar_t wc = *src++;
size_t len = wcrtomb_internal(tbuf, wc);
if (len > n)
len = n;
memcpy(dest, tbuf, len);
if (wc == L'\0')
return org_n - n;
dest += len;
n -= len;
}
return org_n - n;
}
size_t FAST_FUNC mbstowcs(wchar_t *dest, const char *src, size_t n)
{
size_t org_n = n;
if (unicode_is_enabled != 2) {
while (n) {
unsigned char c = *src++;
if (dest)
*dest++ = c;
if (c == 0)
break;
n--;
}
return org_n - n;
}
while (n) {
int bytes;
unsigned c = (unsigned char) *src++;
if (c <= 0x7f) {
if (dest)
*dest++ = c;
if (c == '\0')
break;
n--;
continue;
}
/* 80-7FF -> 110yyyxx 10xxxxxx */
/* 800-FFFF -> 1110yyyy 10yyyyxx 10xxxxxx */
/* 10000-1FFFFF -> 11110zzz 10zzyyyy 10yyyyxx 10xxxxxx */
/* 200000-3FFFFFF -> 111110tt 10zzzzzz 10zzyyyy 10yyyyxx 10xxxxxx */
/* 4000000-FFFFFFFF -> 111111tt 10tttttt 10zzzzzz 10zzyyyy 10yyyyxx 10xxxxxx */
bytes = 0;
do {
c <<= 1;
bytes++;
} while ((c & 0x80) && bytes < 6);
if (bytes == 1)
return (size_t) -1L;
c = (uint8_t)(c) >> bytes;
while (--bytes) {
unsigned ch = (unsigned char) *src++;
if ((ch & 0xc0) != 0x80) {
return (size_t) -1L;
}
c = (c << 6) + (ch & 0x3f);
}
/* TODO */
/* Need to check that c isn't produced by overlong encoding */
/* Example: 11000000 10000000 converts to NUL */
/* 11110000 10000000 10000100 10000000 converts to 0x100 */
/* correct encoding: 11000100 10000000 */
if (c <= 0x7f) { /* crude check */
return (size_t) -1L;
//or maybe: c = 0xfffd; /* replacement character */
}
if (dest)
*dest++ = c;
n--;
}
return org_n - n;
}
int FAST_FUNC iswspace(wint_t wc)
{
return (unsigned)wc <= 0x7f && isspace(wc);
}
int FAST_FUNC iswalnum(wint_t wc)
{
return (unsigned)wc <= 0x7f && isalnum(wc);
}
int FAST_FUNC iswpunct(wint_t wc)
{
return (unsigned)wc <= 0x7f && ispunct(wc);
}
#endif