diff options
Diffstat (limited to 'utils/utf8.c')
| -rw-r--r-- | utils/utf8.c | 139 |
1 files changed, 138 insertions, 1 deletions
diff --git a/utils/utf8.c b/utils/utf8.c index 5c27fa7c6..c0f6b106a 100644 --- a/utils/utf8.c +++ b/utils/utf8.c @@ -297,7 +297,7 @@ utf8_convert_ret utf8_convert(const char *string, size_t len, } slen = len ? len : strlen(string); - /* Worst case = ACSII -> UCS4, so allocate an output buffer + /* Worst case = ASCII -> UCS4, so allocate an output buffer * 4 times larger than the input buffer, and add 4 bytes at * the end for the NULL terminator */ @@ -337,3 +337,140 @@ utf8_convert_ret utf8_convert(const char *string, size_t len, return UTF8_CONVERT_OK; } + +static utf8_convert_ret utf8_convert_html_chunk(iconv_t cd, + const char *chunk, size_t inlen, + char **out, size_t *outlen) +{ + size_t ret, esclen; + uint32_t ucs4; + char *pescape, escape[11]; + + while (inlen > 0) { + ret = iconv(cd, (void *) &chunk, &inlen, (void *) out, outlen); + if (ret != (size_t) -1) + break; + + if (errno != EILSEQ) + return UTF8_CONVERT_NOMEM; + + ucs4 = utf8_to_ucs4(chunk, inlen); + esclen = snprintf(escape, sizeof(escape), "&#x%06x;", ucs4); + pescape = escape; + ret = iconv(cd, (void *) &pescape, &esclen, + (void *) out, outlen); + if (ret == (size_t) -1) + return UTF8_CONVERT_NOMEM; + + esclen = utf8_next(chunk, inlen, 0); + chunk += esclen; + inlen -= esclen; + } + + return UTF8_CONVERT_OK; +} + +/** + * Convert a UTF-8 encoded string into a string of the given encoding, + * applying HTML escape sequences where necessary. + * + * \param string String to convert (NUL-terminated) + * \param encname Name of encoding to convert to + * \param len Length, in bytes, of the input string, or 0 + * \param result Pointer to location to receive result + * \return Appropriate utf8_convert_ret value + */ +utf8_convert_ret utf8_to_html(const char *string, const char *encname, + size_t len, char **result) +{ + iconv_t cd; + const char *in; + char *out, *origout; + size_t off, prev_off, inlen, outlen, origoutlen, esclen; + utf8_convert_ret ret; + char *pescape, escape[11]; + + if (len == 0) + len = strlen(string); + + cd = iconv_open(encname, "UTF-8"); + if (cd == (iconv_t) -1) { + if (errno == EINVAL) + return UTF8_CONVERT_BADENC; + /* default to no memory */ + return UTF8_CONVERT_NOMEM; + } + + /* Worst case is ASCII -> UCS4, with all characters escaped: + * "&#xYYYYYY;", thus each input character may become a string + * of 10 UCS4 characters, each 4 bytes in length */ + origoutlen = outlen = len * 10 * 4; + origout = out = malloc(outlen); + if (out == NULL) { + iconv_close(cd); + return UTF8_CONVERT_NOMEM; + } + + /* Process input in chunks between characters we must escape */ + prev_off = off = 0; + while (off < len) { + /* Must escape '&', '<', and '>' */ + if (string[off] == '&' || string[off] == '<' || + string[off] == '>') { + if (off - prev_off > 0) { + /* Emit chunk */ + in = string + prev_off; + inlen = off - prev_off; + ret = utf8_convert_html_chunk(cd, in, inlen, + &out, &outlen); + if (ret != UTF8_CONVERT_OK) { + free(origout); + iconv_close(cd); + return ret; + } + } + + /* Emit mandatory escape */ + esclen = snprintf(escape, sizeof(escape), + "&#x%06x;", string[off]); + pescape = escape; + ret = utf8_convert_html_chunk(cd, pescape, esclen, + &out, &outlen); + if (ret != UTF8_CONVERT_OK) { + free(origout); + iconv_close(cd); + return ret; + } + + prev_off = off = utf8_next(string, len, off); + } else { + off = utf8_next(string, len, off); + } + } + + /* Process final chunk */ + if (prev_off < len) { + in = string + prev_off; + inlen = len - prev_off; + ret = utf8_convert_html_chunk(cd, in, inlen, &out, &outlen); + if (ret != UTF8_CONVERT_OK) { + free(origout); + iconv_close(cd); + return ret; + } + } + + iconv_close(cd); + + /* Shrink-wrap */ + *result = realloc(origout, origoutlen - outlen + 4); + if (*result == NULL) { + free(origout); + return UTF8_CONVERT_NOMEM; + } + memset(*result + (origoutlen - outlen), 0, 4); + + return UTF8_CONVERT_OK; +} + + |