Sys::Hostname::Long(3) User Contributed Perl Documentation Sys::Hostname::Long(3)

Sys::Hostname::Long - Try every conceivable way to get full hostname

use Sys::Hostname::Long;
$host_long = hostname_long;

How to get the host full name in perl on multiple operating systems (mac, windows, unix* etc)

This is the SECOND release of this code. It has an improved set of tests and improved interfaces - but it is still often failing to get a full host name. This of course is the reason I wrote the module, it is difficult to get full host names accurately on each system. On some systems (eg: Linux) it is dependent on the order of the entries in /etc/hosts.

To make it easier to test I have to generate an output list of all methods. Thus even if the logic is incorrect, it may be possible to get the full name.

Attempt via many methods to get the systems full name. The Sys::Hostname class is the best and standard way to get the system hostname. However it is missing the long hostname.

Special thanks to David Sundstrom and Greg Bacon for the original Sys::Hostname

This is the original list of platforms tested.

MacOS           Macintosh Classic               OK
Win32           MS Windows (95,98,nt,2000...)
                98                              OK
MacOS X         Macintosh 10                    OK
                (other darwin)                  Probably OK (not tested)
Linux           Linux UNIX OS                   OK
                Sparc                           OK
HPUX            H.P. Unix 10?                   Not Tested
Solaris         SUN Solaris 7?                  OK (now)
Irix            SGI Irix 5?                     Not Tested
FreeBSD         FreeBSD                         OK

A new list has now been compiled of all the operating systems so that I can individually keep information on their success.


Mac OS - Not yet tested
Mac OS X - OK 20040315 (v1.1)
4 - Not yet tested
6 (Neutrino) - Not yet tested
3.1 - Not yet tested
95 - Not yet tested
98 - Not yet tested
2000 - Not yet tested

Most unix systems have trouble working out the fully qualified domain name as it to be configured somewhere in the system correctly. For example in most linux systems (debian, ?) the fully qualified name should be the first entry next to the ip number in /etc/hosts     fred.somwhere.special   fred

If it is the other way around, it will fail.


David Dick
Graeme Hart
Piotr Klaban
* Extra code from G
* Dispatch table
* List of all operating systems.

Solaris * Fall back 2 - TCP with DNS works ok * Also can read /etc/defaultdomain file


Originally by Scott Penrose <>

Contributions: Michiel Beijen <>

Copyright (c) 2001,2004,2005,2015 Scott Penrose. All rights reserved. This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

2023-07-25 perl v5.38.0