diff options
Diffstat (limited to 'http.c')
| -rw-r--r-- | http.c | 147 |
1 files changed, 147 insertions, 0 deletions
@@ -71,6 +71,8 @@ static struct curl_slist *no_pragma_header; static struct active_request_slot *active_queue_head; +static char *cached_accept_language; + size_t fread_buffer(char *ptr, size_t eltsize, size_t nmemb, void *buffer_) { size_t size = eltsize * nmemb; @@ -549,6 +551,9 @@ void http_cleanup(void) cert_auth.password = NULL; } ssl_cert_password_required = 0; + + free(cached_accept_language); + cached_accept_language = NULL; } struct active_request_slot *get_active_slot(void) @@ -996,6 +1001,142 @@ static void extract_content_type(struct strbuf *raw, struct strbuf *type, } +/* + * Guess the user's preferred languages from the value in LANGUAGE environment + * variable and LC_MESSAGES locale category if NO_GETTEXT is not defined. + * + * The result can be a colon-separated list like "ko:ja:en". + */ +static const char *get_preferred_languages(void) +{ + const char *retval; + + retval = getenv("LANGUAGE"); + if (retval && *retval) + return retval; + +#ifndef NO_GETTEXT + retval = setlocale(LC_MESSAGES, NULL); + if (retval && *retval && + strcmp(retval, "C") && + strcmp(retval, "POSIX")) + return retval; +#endif + + return NULL; +} + +static void write_accept_language(struct strbuf *buf) +{ + /* + * MAX_DECIMAL_PLACES must not be larger than 3. If it is larger than + * that, q-value will be smaller than 0.001, the minimum q-value the + * HTTP specification allows. See + * http://tools.ietf.org/html/rfc7231#section-5.3.1 for q-value. + */ + const int MAX_DECIMAL_PLACES = 3; + const int MAX_LANGUAGE_TAGS = 1000; + const int MAX_ACCEPT_LANGUAGE_HEADER_SIZE = 4000; + char **language_tags = NULL; + int num_langs = 0; + const char *s = get_preferred_languages(); + int i; + struct strbuf tag = STRBUF_INIT; + + /* Don't add Accept-Language header if no language is preferred. */ + if (!s) + return; + + /* + * Split the colon-separated string of preferred languages into + * language_tags array. + */ + do { + /* collect language tag */ + for (; *s && (isalnum(*s) || *s == '_'); s++) + strbuf_addch(&tag, *s == '_' ? '-' : *s); + + /* skip .codeset, @modifier and any other unnecessary parts */ + while (*s && *s != ':') + s++; + + if (tag.len) { + num_langs++; + REALLOC_ARRAY(language_tags, num_langs); + language_tags[num_langs - 1] = strbuf_detach(&tag, NULL); + if (num_langs >= MAX_LANGUAGE_TAGS - 1) /* -1 for '*' */ + break; + } + } while (*s++); + + /* write Accept-Language header into buf */ + if (num_langs) { + int last_buf_len = 0; + int max_q; + int decimal_places; + char q_format[32]; + + /* add '*' */ + REALLOC_ARRAY(language_tags, num_langs + 1); + language_tags[num_langs++] = "*"; /* it's OK; this won't be freed */ + + /* compute decimal_places */ + for (max_q = 1, decimal_places = 0; + max_q < num_langs && decimal_places <= MAX_DECIMAL_PLACES; + decimal_places++, max_q *= 10) + ; + + sprintf(q_format, ";q=0.%%0%dd", decimal_places); + + strbuf_addstr(buf, "Accept-Language: "); + + for (i = 0; i < num_langs; i++) { + if (i > 0) + strbuf_addstr(buf, ", "); + + strbuf_addstr(buf, language_tags[i]); + + if (i > 0) + strbuf_addf(buf, q_format, max_q - i); + + if (buf->len > MAX_ACCEPT_LANGUAGE_HEADER_SIZE) { + strbuf_remove(buf, last_buf_len, buf->len - last_buf_len); + break; + } + + last_buf_len = buf->len; + } + } + + /* free language tags -- last one is a static '*' */ + for (i = 0; i < num_langs - 1; i++) + free(language_tags[i]); + free(language_tags); +} + +/* + * Get an Accept-Language header which indicates user's preferred languages. + * + * Examples: + * LANGUAGE= -> "" + * LANGUAGE=ko:en -> "Accept-Language: ko, en; q=0.9, *; q=0.1" + * LANGUAGE=ko_KR.UTF-8:sr@latin -> "Accept-Language: ko-KR, sr; q=0.9, *; q=0.1" + * LANGUAGE=ko LANG=en_US.UTF-8 -> "Accept-Language: ko, *; q=0.1" + * LANGUAGE= LANG=en_US.UTF-8 -> "Accept-Language: en-US, *; q=0.1" + * LANGUAGE= LANG=C -> "" + */ +static const char *get_accept_language(void) +{ + if (!cached_accept_language) { + struct strbuf buf = STRBUF_INIT; + write_accept_language(&buf); + if (buf.len > 0) + cached_accept_language = strbuf_detach(&buf, NULL); + } + + return cached_accept_language; +} + /* http_request() targets */ #define HTTP_REQUEST_STRBUF 0 #define HTTP_REQUEST_FILE 1 @@ -1008,6 +1149,7 @@ static int http_request(const char *url, struct slot_results results; struct curl_slist *headers = NULL; struct strbuf buf = STRBUF_INIT; + const char *accept_language; int ret; slot = get_active_slot(); @@ -1033,6 +1175,11 @@ static int http_request(const char *url, fwrite_buffer); } + accept_language = get_accept_language(); + + if (accept_language) + headers = curl_slist_append(headers, accept_language); + strbuf_addstr(&buf, "Pragma:"); if (options && options->no_cache) strbuf_addstr(&buf, " no-cache"); |