Hostname

Hostname
You are encouraged to solve this task according to the task description, using any language you may know.

Find the name of the host on which the routine is running.

Ada

Works with GCC/GNAT <lang ada>with Ada.Text_IO; use Ada.Text_IO; with GNAT.Sockets;

procedure Demo is begin

  Put_Line (GNAT.Sockets.Host_Name);

end Demo;</lang>

ALGOL 68

Works with: ALGOL 68G version Any - tested with release mk15-0.8b.fc9.i386

Works with: POSIX version .1

<lang algol>STRING hostname; get(read OF execve child pipe("/bin/hostname","hostname",""), hostname); print(("hostname: ", hostname, new line))</lang>

AutoHotkey

<lang AutoHotkey>MsgBox % A_ComputerName </lang>

AWK

$ awk 'BEGIN{print ENVIRON["HOST"]}'
E51A08ZD

C

Works with: gcc version 4.0.1

Works with: POSIX version .1

<lang c>#include <limits.h>

1. include <unistd.h>

int main() {

   char name[_POSIX_HOST_NAME_MAX+1];
   gethostname(name, _POSIX_HOST_NAME_MAX+1);
   return 0;

}</lang>

C#

<lang csharp>System.Net.Dns.GetHostName();</lang>

Common Lisp

Another operating system feature that is implemented differently across lisp implementations. Here we show how to create a function that obtains the required result portably by working differently for each supported implementation. This technique is heavily used to make portable lisp libraries. <lang lisp>(defun get-host-name ()

   #+sbcl (machine-instance)
   #+clisp (let ((s (machine-instance))) (subseq s 0 (position #\Space s)))
   #-(or sbcl clisp) (error "get-host-name not implemented"))

</lang>

Library: CFFI

Another way is to use the FFI to access POSIX' gethostname(2):

<lang lisp>(cffi:defcfun ("gethostname" c-gethostname) :int

 (buf :pointer) (len :unsigned-long))

(defun get-hostname ()

 (cffi:with-foreign-object (buf :char 256)
   (unless (zerop (c-gethostname buf 256))
     (error "Can't get hostname"))
   (values (cffi:foreign-string-to-lisp buf))))</lang>

<lang lisp>BOA> (get-hostname) "aurora"</lang>

E

<lang e>makeCommand("hostname")()[0].trim()</lang>

Not exactly a good way to do it. A better way ought to be introduced along with a proper socket interface.

Factor

host-name

Forth

Works with: GNU Forth version 0.7.0

<lang forth> include unix/socket.fs

hostname type </lang>

Fortran

Works with: gfortran

The function/subroutine HOSTNM is a GNU extension. <lang fortran>program HostTest

 character(len=128) :: name 
 call hostnm(name)
 print *, name

end program HostTest</lang>

Groovy

<lang groovy>println InetAddress.localHost.hostName</lang>

Haskell

Library: network

import Network.BSD
main = do hostName <- getHostName
          putStrLn hostName

Icon

procedure main()
  write(&host)
end

IDL

 hostname = GETENV('computername')

J

 > {: sdgethostname coinsert 'jsocket' [ load 'socket'

Java

<lang java> import java.net.*;

class DiscoverHostName {

   public static void main(String[] args) {
       try {
           String hostName = InetAddress.getLocalHost().getHostName();
           System.out.println(hostName);
       } catch (UnknownHostException e) { // Doesn't actually happen, but Java requires it be handled.
       }
   }

} </lang>

MATLAB

<lang Matlab>system('hostname')</lang>

Modula-3

<lang modula3>MODULE Hostname EXPORTS Main;

IMPORT IO, OSConfig;

BEGIN

 IO.Put(OSConfig.HostName() & "\n");

END Hostname.</lang>

Objective-C

<lang objc>NSLog(@"%@", [[NSHost currentHost] name]);</lang>

OCaml

<lang ocaml>Unix.gethostname()</lang>

Octave

Similarly to MATLAB, we could call system command hostname to know the hostname. But we can also call the internal function uname() which returns a structure holding several informations, among these the hostname (nodename):

<lang octave> uname().nodename </lang>

Perl

Works with: Perl version 5.8.6

Library: Sys::HostnameHostname

<lang perl>use Sys::Hostname;

$name = hostname;</lang>

PHP

<lang php>echo $_SERVER['HTTP_HOST'];</lang>

<lang php>echo php_uname('n');</lang>

Works with: PHP version 5.3+

<lang php>echo gethostname();</lang>

Pop11

lvars host = sys_host_name();

PowerShell

Windows systems have the ComputerName environment variable which can be used: <lang powershell>$Env:COMPUTERNAME</lang> Also PowerShell can use .NET classes and methods: <lang powershell>[Net.Dns]::GetHostName()</lang>

Python

Works with: Python version 2.5

<lang python>import socket host = socket.gethostname()</lang>

R

Sys.info provides information about the platform that R is running on. The following code returns the hostname as a string. <lang R> Sys.info()"nodename" </lang> Note that Sys.info isn't available on all platforms. As an alternative, you can call an OS command. The following code prints the hostname to the console (or other connection), but returns an int. <lang R> system("hostname") </lang>

Ruby

<lang ruby>require 'socket' host = Socket.gethostname</lang>

Scheme

Works with: Chicken Scheme

<lang scheme>(use posix) (get-host-name)</lang>

Slate

<lang slate>Platform current nodeName</lang>

Standard ML

<lang sml>NetHostDB.getHostName ()</lang>

Tcl

The basic introspection tool in TCL is the info command. It can be used to find out about the version of the current Tcl or Tk, the available commands and libraries, variables, functions, the level of recursive interpreter invocation, and, amongst a myriad other things, the name of the current machine:

<lang Tcl>set hname [info hostname]</lang>

Toka

2 import gethostname
1024 chars is-array foo
foo 1024 gethostname
foo type

UNIX Shell

hostname

or

uname -n

Ursala

The user-defined hostname function ignores its argument and returns a string. <lang Ursala>

1. import cli

hostname = ~&hmh+ (ask bash)/<>+ <'hostname'>!</lang> For example, the following function returns the square root of its argument if it's running on host kremvax, but otherwise returns the square. <lang Ursala>#import flo

creative_accounting = (hostname== 'kremvax')?(sqrt,sqr)</lang>