Resolve the SEC user agent

Resolves the SEC user agent from, in order, an explicit argument, the SEC_USER_AGENT environment variable, and getOption("HTTPUserAgent"). In an interactive session, when no valid value can be resolved, the helper asks for a user agent and offers to persist it in either project-level .Renviron or user-level ~/.Renviron.

Usage

dera_user_agent(user_agent = NULL, prompt = interactive())

Arguments

user_agent

Optional SEC user-agent override.

prompt

If TRUE, prompt interactively when no user agent can be resolved.

Value

A non-empty character string containing an email address.