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Is a host itself a public suffix?

Source: R/query.R
is_public_suffix.Rd

TRUE exactly when the valid canonical host equals its own public suffix under the selected policy. Returns NA whenever public_suffix() would return NA (missing or invalid input, or an unresolved host under unknown = "na"). Under the default unknown = "default", an unlisted single label such as "madeuptld" is TRUE via the implicit * rule; ask unknown = "na" to test explicit membership instead.

Usage

is_public_suffix(
  domain,
  section = c("all", "icann", "private"),
  unknown = c("default", "na"),
  invalid = c("na", "error")
)

Arguments

domain

Character vector of DNS hostnames (not URLs). Each element may be a mixed-case ASCII, Unicode, or A-label hostname, a single label, or a hostname with exactly one terminal root dot. See Input contract.

section

Which rule sections are eligible: "all" (default; ICANN and PRIVATE), "icann", or "private". Section filtering happens before prevailing-rule selection, so "private" does not silently add ICANN rules; a host matching no rule in the section falls through to the implicit default rule unless unknown = "na".

unknown

"default" (default) applies the spec's implicit * rule, so an unlisted single label is its own public suffix; "na" returns NA when no explicit rule in the selected section matches.

invalid

"na" (default) returns NA for each invalid element without a warning; "error" aborts on the first invalid element, reporting its 1-based index.

Value

A logical vector with length(domain), preserving the names of domain.

Input contract

NA is treated as missing (returns NA), not invalid. Invalid elements include empty or whitespace-only strings, leading or consecutive dots, URL syntax, IPv6 addresses, canonical dotted-decimal IPv4 literals, and labels that fail hostname/IDNA validation. Wrong argument types and non-scalar or unknown option values always abort regardless of invalid.

See also

public_suffix()

Examples

is_public_suffix("com")
#> [1] TRUE
is_public_suffix("example.com")
#> [1] FALSE
is_public_suffix("madeuptld")
#> [1] TRUE
is_public_suffix("madeuptld", unknown = "na")
#> [1] NA