diff options
| -rw-r--r-- | src/mds-kbdc/string.c | 37 |
1 files changed, 37 insertions, 0 deletions
diff --git a/src/mds-kbdc/string.c b/src/mds-kbdc/string.c index ca33b83..82797f3 100644 --- a/src/mds-kbdc/string.c +++ b/src/mds-kbdc/string.c @@ -82,3 +82,40 @@ char32_t* string_decode(const char* restrict string) return rc[length] = -1, rc; } + +/** + * Convert a -1-terminated UTF-32 string to a NUL-terminated Modified UTF-8 string. + * + * @param string The UTF-32 string. + * @return The string in UTF-8, `NULL` on error. + */ +char* string_encode(const char32_t* restrict string) +{ + size_t i, j, n = string_length(string); + char* restrict rc; + + /* Allocated Modified UTF-8 string. */ + if (xmalloc(rc, 6 * n + 1, char)) + return NULL; + + /* Convert to Modified UTF-8. */ + for (i = j = 0; i < n; i++) + { +#define _c(s) rc[j++] = (char)(((c >> (s)) & 0x3F) | 0x80) +#define _t(s) t < (char32_t)(1L << s) + char32_t c = string[i]; + if (c == 0) rc[j++] = 0xC0, rc[j++] = 0x80; + else if (_t( 7)) rc[j++] = (char)c; + else if (_t(11)) rc[j++] = (char)((c >> 6) | 0xC0), _c( 0); + else if (_t(16)) rc[j++] = (char)((c >> 12) | 0xE0), _c( 6), _c( 0); + else if (_t(21)) rc[j++] = (char)((c >> 18) | 0xF0), _c(12), _c( 6), _c( 0); + else if (_t(26)) rc[j++] = (char)((c >> 24) | 0xF8), _c(18), _c(12), _c( 6), _c(0); + else rc[j++] = (char)((c >> 30) | 0xFC), _c(24), _c(18), _c(12), _c(6), _c(0); +#undef _t +#undef _c + } + + /* NUL-terminate and return. */ + return rc[j] = '\0', rc; +} + |