View source: R/ip_to_hostname.R
ip_to_hostname | R Documentation |
Perform reverse and forward DNS resolution.
Note: These functions are significantly slower than others in the ipaddress package.
ip_to_hostname(x)
ip_to_hostname_all(x)
hostname_to_ip(x)
hostname_to_ip_all(x)
x |
|
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.
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
The base function nsl()
provides forward DNS resolution to IPv4 addresses,
but only on Unix-like systems.
## Not run:
hostname_to_ip("r-project.org")
ip_to_hostname(hostname_to_ip("r-project.org"))
## End(Not run)
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