Function getfqdn

Lib/socket.py:808–832

Get fully qualified domain name from name. An empty argument is interpreted as meaning the local host. First the hostname returned by gethostbyaddr() is checked, then possibly existing aliases. In case no FQDN is available and `name` was given, it is returned unchanged. If `name` w

(name='')

def getfqdn(name=''):
    """Get fully qualified domain name from name.

    An empty argument is interpreted as meaning the local host.

    First the hostname returned by gethostbyaddr() is checked, then
    possibly existing aliases. In case no FQDN is available and `name`
    was given, it is returned unchanged. If `name` was empty, '0.0.0.0' or '::',
    hostname from gethostname() is returned.
    """
    name = name.strip()
    if not name or name in ('0.0.0.0', '::'):
        name = gethostname()
    try:
        hostname, aliases, ipaddrs = gethostbyaddr(name)
    except error:
        pass
    else:
        aliases.insert(0, hostname)
        for name in aliases:
            if '.' in name:
                break
        else:
            name = hostname
    return name


_GLOBAL_DEFAULT_TIMEOUT = object()