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Translate address to/from hostname

Source: R/ip_to_hostname.R
ip_to_hostname.Rd

Perform reverse and forward DNS resolution.

Note: These functions are significantly slower than others in the ipaddress package.

Usage

ip_to_hostname(x)

ip_to_hostname_all(x)

hostname_to_ip(x)

hostname_to_ip_all(x)

Arguments

x

  • ip_to_hostname(): An ip_address vector

  • hostname_to_ip(): A character vector of hostnames

Value

  • ip_to_hostname(): A character vector

  • ip_to_hostname_all(): A list of character vectors

  • hostname_to_ip(): An ip_address vector

  • hostname_to_ip_all(): A list of ip_address vectors

Details

These functions require an internet connection. Before processing the input vector, we first check that a known hostname can be resolved. If this fails, an error is raised.

If DNS lookup cannot resolve an input, then NA is returned for that input. If an error occurs during DNS lookup, then a warning is emitted and NA is returned for that input.

DNS resolution performs a many-to-many mapping between IP addresses and hostnames. For this reason, there are two versions of each function. The regular version returns just the first value and the _all() suffix version returns all values.

See also

The base function nsl() provides forward DNS resolution to IPv4 addresses, but only on Unix-like systems.

Examples

if (FALSE) { # \dontrun{
hostname_to_ip("r-project.org")

ip_to_hostname(hostname_to_ip("r-project.org"))
} # }