FAQ: How do I find out my hostname/domainname/IP address?

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This message is one of several periodic postings to comp.lang.perl.misc
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9.23: How do I find out my hostname/domainname/IP address?

    The normal way to find your own hostname is to call the "`hostname`"
    program. While sometimes expedient, this has some problems, such as not
    knowing whether you've got the canonical name or not. It's one of those
    tradeoffs of convenience versus portability.

    The Sys::Hostname module (part of the standard perl distribution) will
    give you the hostname after which you can find out the IP address
    (assuming you have working DNS) with a gethostbyname() call.

        use Socket;
        use Sys::Hostname;
        my $host = hostname();
        my $addr = inet_ntoa(scalar gethostbyname($host || 'localhost'));

    Probably the simplest way to learn your DNS domain name is to grok it
    out of /etc/resolv.conf, at least under Unix. Of course, this assumes
    several things about your resolv.conf configuration, including that it

    (We still need a good DNS domain name-learning method for non-Unix


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