psl.load_file(path)

Loads a psl from the given file path. On success, returns a psl object. On failure, returns nil.

psl.load_fp(file)

Loads a psl from the given lua file object. On success, returns a psl object. On failure, returns nil.

psl.builtin()

Returns the psl built in to libpsl. If it exists, returns a psl object. If libpsl was compiled without one, returns nil.

psl.builtin_file_time()

Returns the time-stamp of the file used to build the built in psl. If it exists, returns the time-stamp as an integer. If libpsl was compiled without one, returns nil.

psl.builtin_sha1sum()

Returns the SHA1 checksum of the file used to build the built in psl. If it exists, returns the checksum as a string of lower-case hex digits. If libpsl was compiled without one, returns nil.

psl.builtin_filename()

Returns the file name of the file used to build the built in psl. If it exists, returns a string. If libpsl was compiled without one, returns nil.

psl.builtin_outdated()

Returns a boolean indicating if the built-in data is older than the file currently at psl.builtin_filename().

Note: This function will not exist if lua-psl is compiled against libpsl 0.10 or earlier.

psl.dist_filename()

Returns a string containing the path to your computer’s default psl database location. If libpsl was not configured with one or was configured with an empty path, returns nil.

Note: This function will not exist if lua-psl is compiled against libpsl 0.15 or earlier.

psl.latest(filename)

This function loads the the latest available PSL data from the following locations:

1. filename (application specific filename, may be nil)
2. default psl database location (as returned from psl.dist_filename())
3. built-in PSL data (as returned from psl.builtin())
4. location of built-in data (as returned from psl.builtin_filename())

If none of the locations contain a valid psl object then returns nil.

Note: This function will not exist if lua-psl is compiled against libpsl 0.15 or earlier.

psl.get_version()

Returns a string containing the version of libpsl.

psl.check_version_number(version)

Check if the given version number is at least the current library version number.

Returns the current library version number if the given version number is at least the version of the library, otherwise returns false. If the version argument is missing, nil or 0 then returns the current library version number without performing a check.

Note: This function will not exist if lua-psl is compiled against libpsl 0.10 or earlier.

psl.str_to_utf8lower(str, encoding, locale)

Converts a string to UTF-8 lower-case + NFKC representation.

encoding (optional) is the charset encoding of str. locale (optional) is the locale of str.

On success, returns a string. On failure, returns nil.

psl.VERSION

The libpsl version as a string.

Note: This constant will not exist if lua-psl is compiled against libpsl 0.10 or earlier.

psl.VERSION_NUMBER

The libpsl version as an integer.

Note: This constant will not exist if lua-psl is compiled against libpsl 0.10 or earlier.

psl.VERSION_MAJOR

The libpsl major version as an integer.

Note: This constant will not exist if lua-psl is compiled against libpsl 0.10 or earlier.

psl.VERSION_MINOR

The libpsl minor version as an integer.

Note: This constant will not exist if lua-psl is compiled against libpsl 0.10 or earlier.

psl.VERSION_PATCH

The libpsl patch version as an integer.

Note: This constant will not exist if lua-psl is compiled against libpsl 0.10 or earlier.

psl.TYPE

A table containing constants for psl:is_public_suffix().

• ANY
• ICANN
• PRIVATE
• NO_STAR_RULE (if compiled against libpsl 0.20 or newer)

Note: This table will not exist if lua-psl is compiled against libpsl 0.11 or earlier.

psl:free()

Manually free the resources used by the psl object.

Will be called automatically if the psl object is collected.

psl:is_public_suffix(domain, type)

Checks if domain is on the public suffix list.

domain should be a UTF-8 string.

type (optional) should be one of the psl.TYPE constants; the default behaviour is psl.TYPE.ANY. This argument is only supported if compiled against libpsl 0.12.0 or above.

Returns a boolean.

psl:unregistrable_domain(domain)

domain should be a UTF-8 string.

Returns the longest public suffix part of domain as a string. If domain does not contain a public suffix, returns nil.

psl:registrable_domain(domain)

domain should be a UTF-8 string.

Returns the shortest private suffix part of domain as a string. If domain does not contain a private suffix, returns nil.

psl:suffix_count()

Returns the number of public suffixes as an integer.

When the count is unknown, returns nil.

psl:suffix_exception_count()

Returns the number of public suffix exceptions as an integer.

When the count is unknown, returns nil.

psl:suffix_wildcard_count()

Returns the number of public suffix wild-cards as an integer.

When the count is unknown, returns nil.

Note: This function will not exist if lua-psl is compiled against libpsl 0.10 or earlier.

psl:is_cookie_domain_acceptable(hostname, cookie_domain)

Checks whether cookie_domain is an acceptable cookie domain value for the request hostname.

hostname and cookie_domain should be UTF-8 strings.

Returns a boolean.

local psl = assert(require "psl".builtin())
assert(psl:is_cookie_domain_acceptable("www.example.com", "example.com"))
assert(not psl:is_cookie_domain_acceptable("example.com", "com"))