realhostname_sa
—
convert a struct sockaddr to the real
host name
System Utilities Library (libutil,
-lutil)
The function
realhostname_sa
()
converts addr to the corresponding host name. This is
done by resolving addr to a host name and then
ensuring that the host name resolves back to addr.
host must point to a buffer of at least
hsize bytes, and will always be written to by this
function.
If the name resolution does not work both ways or if the host name
is longer than hsize bytes,
getnameinfo(3)
with NI_NUMERICHOST specified, is used to convert addr
to an ASCII form.
If the string written to host is
hsize bytes long, host will not
be NUL terminated.
The realhostname_sa
() function will return
one of the following constants which are defined in
<libutil.h>
:
HOSTNAME_FOUND
- A valid host name was found.
HOSTNAME_INCORRECTNAME
- A host name was found, but it did not resolve back to the passed
ip. host now contains the
numeric value of ip.
HOSTNAME_INVALIDADDR
- ip could not be resolved. host
now contains the numeric value of ip.
HOSTNAME_INVALIDNAME
- A host name was found, but it could not be resolved back to any ip number.
host now contains the numeric value of
ip.