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5. Content negotiation

Available inall subroutines.

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

This function takes the following parameters:

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

Example

set bereq.http.Accept-Charset =
  accept.charset_lookup("iso-8859-5:iso-8859-2", "utf-8",
    req.http.Accept-Charset);

Try it out

accept.charset_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.