This includes two breaking changes:
- the hostname is not resolved in the case of an IP address.
- a hostname with a trailing period (FQDN) is not matched.
This brings the basic implementation in line with curl behaviour, with
the addition of full IP address and range matching (curl does not
differentiate between IP addresses host names).
The NO_PROXY environment variable can be set to either a comma-separated
list of host names that should not use a proxy, or single asterisk `*`
to match all hosts.
- Port numbers can be included by prefixing the port with a colon `:`.
- IP addresses can be used, but must be enclosed in square brackets
`[...]` if they include a port number.
- IP address ranges can specified in CIDR notation, separating the IP
address and prefix-length with a forward slash `/`.
Jordi Boggiano