Module: HostnameRegexes

Included in:

TopinambourRegex

Defined in:

lib/terminal_regex.rb

Constant Summary

HOSTNAMESEGMENTCHARS_CLASS =

Either an alphanumeric character or dash; or if [negative lookahead] not ASCII then any graphical Unicode character. A segment can consist entirely of numbers. (Note: PCRE doesn’t support character class subtraction/intersection.) */

"(?x: [-[:alnum:]] | (?! [[:ascii:]] ) [[:graph:]] )"

HOSTNAME1 =

A hostname of at least 1 component. The last component cannot be entirely numbers. E.g. “foo”, “example.com”, “1234.com”, but not “foo.123” */

"(?x: (?: #{HOSTNAMESEGMENTCHARS_CLASS}+ \\. )* " + "#{HOSTNAMESEGMENTCHARS_CLASS}* (?! [0-9] ) #{HOSTNAMESEGMENTCHARS_CLASS}+ )"

HOSTNAME2 =

A hostname of at least 2 components. The last component cannot be entirely numbers. E.g. “example.com”, “1234.com”, but not “1234.56” */

"(?x: (?: #{HOSTNAMESEGMENTCHARS_CLASS}+ \\.)+ #{HOSTNAME1} )"

URL_HOST =

For URL: Hostname, IPv4, or bracket-enclosed IPv6, e.g. “example.com”, “1.2.3.4”, “[::1]” */

"(?x: #{HOSTNAME1} | (?&IPV4) | \\[ (?&IPV6) \\] )"

EMAIL_HOST =

For e-mail: Hostname of at least two segments, or bracket-enclosed IPv4 or IPv6, e.g. “example.com”, “[1.2.3.4]”, “[::1]”. Technically an e-mail with a single-component hostname might be valid on a local network, but let’s avoid tons of false positives (e.g. in a typical shell prompt). */

"(?x: #{HOSTNAME2} | \\[ (?: (?&IPV4) | (?&IPV6) ) \\] )"