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5. Content negotiation

Available inall subroutines.

Selects the best match from a string in the format of an Accept-Encoding header's value in the listed content encodings using the algorithm described in Section 5.3.3 of RFC 7231.

This function takes the following parameters:

1. a colon-separated list of content encodings available for the resource,
2. a fallback return value,
3. a string representing an Accept-Encoding header's value.

This function does not have special handling of x-compress or x-gzip values.

Example

set bereq.http.Accept-Encoding =
  accept.encoding_lookup("compress:gzip", "identity",
    req.http.Accept-Encoding);

Try it out

accept.encoding_lookup is used in the following code examples. Examples apply VCL to real-world use cases and can be deployed as they are, or adapted for your own service. See the full list of code examples for more inspiration.

Click RUN on a sample below to provision a Fastly service, execute the code on Fastly, and see how the function behaves.