Authorized indicates whether an HTTP request is authorized to trigger the hook, either through the "Authorization" header or the "authorization" URL query parameter.

BoolOption parses and returns the value of a boolean option, either from command line flags or from an environment variable.

Fail prints a message in red to the standard error stream (as long as the `quiet` option is false) and exits the process with a non-zero code.

Print prints a message to the standard error stream (as long as the `quiet` option is false).

StringOption parses and returns the value of a free-form text option, either from command line flags or from an environment variable.

Uint64Option parses and returns the value of an unsigned integer option, either from command line flags or from an environment variable.

EnvPrefix is the prefix common to environment variables for monohook.

ErrorHandler can be called if an error occurs while parsing a command line option.