```lua
> f.parse_url("http:\\")
nil Failed to parse URL
> r = f.parse_url("http://localhost/")
> for k,v in pairs(r) do; print('\t',k,v); end
user
scheme http
host localhost
doc /
password
> r = f.parse_url("http://user:pass@localhost:1999/rain?beret=raspberry")
> for k,v in pairs(r) do; print('\t',k,v); end
user user
doc /rain?beret=raspberry
scheme http
host localhost
port 1999
password pass
> f.get_url("file:///var/run/motd", "/tmp/m")
true
> f.get_url("http://w3.org/", "/tmp/w")
true
> f.get_url("https://freebsd.org/", "/tmp/f")
true
> f.get_url("https://invalid.site/", "/tmp/i")
nil Failed to read from URL: No error: 0
> f.get_url("https://wrong.host.badssl.com/", "/tmp/i")
SSL certificate subject doesn't match host wrong.host.badssl.com
nil Failed to read from URL: Authentication error
>
```