decompression gzip data with curl

Note that this option has been renamed to CURLOPT_ACCEPT_ENCODING.

As stated by the documentation:

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

So it does decode (i.e decompress) the response. Three encoding are supported: "identity" (does nothing), "zlib" and "gzip". Alternatively you can pass an empty string which creates an Accept-Encoding: header containing all supported encodings.

At last, httpbin is handy to test it out as it contains a dedicated endpoint that returns gzip content. Here's an example:

#include <curl/curl.h>intmain(void){  CURLcode rc;  CURL *curl;  curl = curl_easy_init();  curl_easy_setopt(curl, CURLOPT_URL, "http://httpbin.org/gzip");  curl_easy_setopt(curl, CURLOPT_ACCEPT_ENCODING, "gzip");  curl_easy_setopt(curl, CURLOPT_VERBOSE, 1L);  rc = curl_easy_perform(curl);  curl_easy_cleanup(curl);  return (int) rc;}

It sends:

GET /gzip HTTP/1.1Host: httpbin.orgAccept: */*Accept-Encoding: gzip

And gets as response:

HTTP/1.1 200 OKAccess-Control-Allow-Origin: *Content-Encoding: gzipContent-Type: application/json...

And a JSON response (thus decompressed) is written on stdout.

c++ CURL library does not compress/decompress your data. you must do it yourself.

        CURL *curl = curl_easy_init();        struct curl_slist *headers=NULL;        headers = curl_slist_append(headers, "Accept: application/json");        headers = curl_slist_append(headers, "Content-Type: application/json");        headers = curl_slist_append(headers, "Content-Encoding: gzip");        curl_easy_setopt(curl, CURLOPT_HTTPHEADER, headers );        curl_easy_setopt(curl, CURLOPT_ENCODING, "gzip");        curl_easy_setopt(curl, CURLOPT_POSTFIELDS, zipped_data.data() );        curl_easy_setopt(curl, CURLOPT_POSTFIELDSIZE, zipped_data.size() );