.TH dnsname 1

.SH NAME
dnsname \- does a reverse lookup for the IP address

.SH SYNOPSIS
.B dnsname 
.I a.b.c.d

.SH DESCRIPTION
.B dnsname
does a reverse lookup for the IP address
.IR a.b.c.d .
It prints the first domain name for that address.
If no domain names are listed in DNS,
.B dnsname
prints a blank line.
You can list several IP addresses;
.B dnsname
prints each result on a separate line.

There is also a
.BR dnsfilter (1)
program
that reads IP addresses from its input
and performs many reverse lookups in parallel.

Normally 
.B dnsname
exits 0.
If 
.B dnsname
encounters a temporary problem
that prevents it from determining the domain name,
it prints an error message and exits 111.

.SH SEE ALSO
dnsip(1),
dnsipq(1),
dnsmx(1),
dnstxt(1),
dnsqr(1),
dnsq(1),
dnstrace(1)

http://cr.yp.to/djbdns.html