scrcpy/app/src/str_util.c
Romain Vimont 0a7fe7ad57 Add helpers to truncate UTF-8 at code points
This will help to avoid truncating a UTF-8 string in the middle of a
code point, producing an invalid UTF-8 result.
2019-05-30 22:30:18 +02:00

95 lines
2 KiB
C

#include "str_util.h"
#include <stdlib.h>
#include <string.h>
#ifdef _WIN32
# include <windows.h>
# include <tchar.h>
#endif
#include <SDL2/SDL_stdinc.h>
size_t
xstrncpy(char *dest, const char *src, size_t n) {
size_t i;
for (i = 0; i < n - 1 && src[i] != '\0'; ++i)
dest[i] = src[i];
if (n)
dest[i] = '\0';
return src[i] == '\0' ? i : n;
}
size_t
xstrjoin(char *dst, const char *const tokens[], char sep, size_t n) {
const char *const *remaining = tokens;
const char *token = *remaining++;
size_t i = 0;
while (token) {
if (i) {
dst[i++] = sep;
if (i == n)
goto truncated;
}
size_t w = xstrncpy(dst + i, token, n - i);
if (w >= n - i)
goto truncated;
i += w;
token = *remaining++;
}
return i;
truncated:
dst[n - 1] = '\0';
return n;
}
char *
strquote(const char *src) {
size_t len = strlen(src);
char *quoted = SDL_malloc(len + 3);
if (!quoted) {
return NULL;
}
memcpy(&quoted[1], src, len);
quoted[0] = '"';
quoted[len + 1] = '"';
quoted[len + 2] = '\0';
return quoted;
}
size_t
utf8_truncation_index(const char *utf8, size_t max_len) {
size_t len = strlen(utf8);
if (len <= max_len) {
return len;
}
len = max_len;
// see UTF-8 encoding <https://en.wikipedia.org/wiki/UTF-8#Description>
while ((utf8[len] & 0x80) != 0 && (utf8[len] & 0xc0) != 0xc0) {
// the next byte is not the start of a new UTF-8 codepoint
// so if we would cut there, the character would be truncated
len--;
}
return len;
}
#ifdef _WIN32
wchar_t *
utf8_to_wide_char(const char *utf8) {
int len = MultiByteToWideChar(CP_UTF8, 0, utf8, -1, NULL, 0);
if (!len) {
return NULL;
}
wchar_t *wide = SDL_malloc(len * sizeof(wchar_t));
if (!wide) {
return NULL;
}
MultiByteToWideChar(CP_UTF8, 0, utf8, -1, wide, len);
return wide;
}
#endif