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. Four 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 will be 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

       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_TRANSFER_ENCODING(3), CURLOPT_HTTPHEADER(3), CURLOPT_HTTP_CONTENT_DECODING(3),