noble (3) CURLOPT_ACCEPT_ENCODING.3.gz

NAME

       CURLOPT_ACCEPT_ENCODING - automatic decompression of HTTP downloads

SYNOPSIS

       #include <curl/curl.h>

       CURLcode curl_easy_setopt(CURL *handle, CURLOPT_ACCEPT_ENCODING, char *enc);

DESCRIPTION

       Pass a char * argument specifying what encoding you would like.

       Sets  the  contents  of  the  Accept-Encoding:  header sent in an HTTP request, and enables decoding of a
       response when a Content-Encoding: header is received.

       libcurl potentially supports several different compressed encodings depending on what  support  that  has
       been built-in.

       To  aid  applications  not  having to bother about what specific algorithms this particular libcurl build
       supports, libcurl allows a zero-length string to be set ("") to ask for an Accept-Encoding: header to  be
       used that contains all built-in supported encodings.

       Alternatively,  you  can  specify exactly the encoding or list of encodings you want in the response. The
       following encodings are supported: identity, meaning non-compressed, deflate which requests the server to
       compress  its  response  using  the  zlib  algorithm, gzip which requests the gzip algorithm, (since curl
       7.57.0) br which is brotli and (since curl 7.72.0) zstd which is zstd. Provide them in the  string  as  a
       comma-separated list of accepted encodings, like: "br, gzip, deflate".

       Set  CURLOPT_ACCEPT_ENCODING(3) to NULL to explicitly disable it, which makes libcurl not send an Accept-
       Encoding: header and not decompress received contents automatically.

       You can also opt to just include the Accept-Encoding: header in your request  with  CURLOPT_HTTPHEADER(3)
       but then there is no automatic decompressing when receiving data.

       This  is  a request, not an order; the server may or may not do it.  This option must be set (to any non-
       NULL value) or else any unsolicited encoding done by the server is ignored.

       Servers might respond with Content-Encoding even without  getting  a  Accept-Encoding:  in  the  request.
       Servers might respond with a different Content-Encoding than what was asked for in the request.

       The  Content-Length:  servers  send  for  a compressed response is supposed to indicate the length of the
       compressed content so when auto decoding is enabled it may not match the sum of  bytes  reported  by  the
       write callbacks (although, sending the length of the non-compressed content is a common server mistake).

       The application does not have to keep the string around after setting this option.

DEFAULT

       NULL

PROTOCOLS

       HTTP

EXAMPLE

       int main(void)
       {
         CURL *curl = curl_easy_init();
         if(curl) {
           curl_easy_setopt(curl, CURLOPT_URL, "https://example.com");

           /* enable all supported built-in compressions */
           curl_easy_setopt(curl, CURLOPT_ACCEPT_ENCODING, "");

           /* Perform the request */
           curl_easy_perform(curl);
         }
       }

AVAILABILITY

       This option was called CURLOPT_ENCODING before 7.21.6

       The  specific  libcurl  you  are  using  must have been built with zlib to be able to decompress gzip and
       deflate responses, with the brotli library to decompress brotli responses and with the  zstd  library  to
       decompress zstd responses.

RETURN VALUE

       Returns CURLE_OK if the option is supported, CURLE_UNKNOWN_OPTION if not, or CURLE_OUT_OF_MEMORY if there
       was insufficient heap space.

SEE ALSO

       CURLOPT_HTTP_CONTENT_DECODING(3), CURLOPT_HTTPHEADER(3), CURLOPT_TRANSFER_ENCODING(3)