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CURLOPT_ACCEPT_ENCODING(3) curl_easy_setopt options
CURLOPT_ACCEPT_ENCODING - enables automatic decompression of HTTP
CURLcode curl_easy_setopt(CURL *handle, CURLOPT_ACCEPT_ENCODING, char
Pass a char * argument specifying what encoding you'd 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
CURL *curl = curl_easy_init();
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 */
This option was called CURLOPT_ENCODING before 7.21.6
The specific libcurl you're 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
Returns CURLE_OK if the option is supported, CURLE_UNKNOWN_OPTION if
not, or CURLE_OUT_OF_MEMORY if there was insufficient heap space.
libcurl 7.73.0 September 16, 2020 CURLOPT_ACCEPT_ENCODING(3)