import { environ } from "https://deno.land/x/denops_std@v4.1.4/function/mod.ts";
Return all of environment variables as dictionary. You can check if an environment variable exists like this: :echo has_key(environ(), 'HOME') Note that the variable name may be CamelCase; to ignore case use this: :echo index(keys(environ()), 'HOME', 0, 1) != -1