rules

Documentation

Index

• func IsEmail(val string) bool
• func IsHostAndPort(str string, portRequired bool) bool
• func IsHostname(val string) bool
• func IsIP(str string, version int64) bool
• func IsIPPrefix(str string, version int64, strict bool) bool
• func IsURI(val string) bool
• func IsURIRef(val string) bool

Functions

func IsEmail

func IsEmail(val string) bool

IsEmail reports whether val is an email address, for example "foo@example.com".

Conforms to the definition for a valid email address from the HTML standard. Note that this standard willfully deviates from RFC 5322, which allows many unexpected forms of email addresses and will easily match a typographical error.

func IsHostAndPort

func IsHostAndPort(str string, portRequired bool) bool

IsHostAndPort returns true if the string is a valid host/port pair, for example "example.com:8080".

If the argument portRequired is true, the port is required. If the argument is false, the port is optional.

The host can be one of:

• An IPv4 address in dotted decimal format, for example "192.168.0.1".
• An IPv6 address enclosed in square brackets, for example "[::1]".
• A hostname, for example "example.com".

The port is separated by a colon. It must be non-empty, with a decimal number in the range of 0-65535, inclusive.

func IsHostname

func IsHostname(val string) bool

IsHostname returns true if the string is a valid hostname, for example "foo.example.com".

A valid hostname follows the rules below:

• The name consists of one or more labels, separated by a dot (".").
• Each label can be 1 to 63 alphanumeric characters.
• A label can contain hyphens ("-"), but must not start or end with a hyphen.
• The right-most label must not be digits only.
• The name can have a trailing dot, for example "foo.example.com.".
• The name can be 253 characters at most, excluding the optional trailing dot.

func IsIP

func IsIP(str string, version int64) bool

IsIP returns true if the string is an IPv4 or IPv6 address, optionally limited to a specific version.

Version 0 means either 4 or 6. Passing a version other than 0, 4, or 6 always returns false.

IPv4 addresses are expected in the dotted decimal format, for example "192.168.5.21". IPv6 addresses are expected in their text representation, for example "::1", or "2001:0DB8:ABCD:0012::0".

Both formats are well-defined in the internet standard RFC 3986. Zone identifiers for IPv6 addresses (for example "fe80::a%en1") are supported.

func IsIPPrefix

func IsIPPrefix(
	str string,
	version int64,
	strict bool,
) bool

IsIPPrefix returns true if the string is a valid IP with prefix length, optionally limited to a specific version (v4 or v6), and optionally requiring the host portion to be all zeros.

An address prefix divides an IP address into a network portion, and a host portion. The prefix length specifies how many bits the network portion has. For example, the IPv6 prefix "2001:db8:abcd:0012::0/64" designates the left-most 64 bits as the network prefix. The range of the network is 2**64 addresses, from 2001:db8:abcd:0012::0 to 2001:db8:abcd:0012:ffff:ffff:ffff:ffff.

An address prefix may include a specific host address, for example "2001:db8:abcd:0012::1f/64". With strict = true, this is not permitted. The host portion must be all zeros, as in "2001:db8:abcd:0012::0/64".

The same principle applies to IPv4 addresses. "192.168.1.0/24" designates the first 24 bits of the 32-bit IPv4 as the network prefix.

func IsURI

func IsURI(val string) bool

IsURI reports whether val is a URI, for example "https://example.com/foo/bar?baz=quux#frag".

URI is defined in the internet standard RFC 3986. Zone Identifiers in IPv6 address literals are supported (RFC 6874).

func IsURIRef

func IsURIRef(val string) bool

IsURIRef reports whether val is a URI Reference - a URI such as "https://example.com/foo/bar?baz=quux#frag", or a Relative Reference such as "./foo/bar?query".

URI, URI Reference, and Relative Reference are defined in the internet standard RFC 3986. Zone Identifiers in IPv6 address literals are supported (RFC 6874).