diff options
Diffstat (limited to 'utf8.c')
| -rw-r--r-- | utf8.c | 39 |
1 files changed, 39 insertions, 0 deletions
@@ -531,3 +531,42 @@ char *reencode_string(const char *in, const char *out_encoding, const char *in_e return out; } #endif + +/* + * Returns first character length in bytes for multi-byte `text` according to + * `encoding`. + * + * - The `text` pointer is updated to point at the next character. + * - When `remainder_p` is not NULL, on entry `*remainder_p` is how much bytes + * we can consume from text, and on exit `*remainder_p` is reduced by returned + * character length. Otherwise `text` is treated as limited by NUL. + */ +int mbs_chrlen(const char **text, size_t *remainder_p, const char *encoding) +{ + int chrlen; + const char *p = *text; + size_t r = (remainder_p ? *remainder_p : SIZE_MAX); + + if (r < 1) + return 0; + + if (is_encoding_utf8(encoding)) { + pick_one_utf8_char(&p, &r); + + chrlen = p ? (p - *text) + : 1 /* not valid UTF-8 -> raw byte sequence */; + } + else { + /* + * TODO use iconv to decode one char and obtain its chrlen + * for now, let's treat encodings != UTF-8 as one-byte + */ + chrlen = 1; + } + + *text += chrlen; + if (remainder_p) + *remainder_p -= chrlen; + + return chrlen; +} |