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

with Ada.Text_IO; use Ada.Text_IO;
with GNAT.Sockets;
 
procedure Demo is
begin
   Put_Line (GNAT.Sockets.Host_Name);
end Demo;

ALGOL 68

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

Works with: POSIX version .1

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

Aikido

 
println (System.hostname)
 

AutoHotkey

MsgBox % A_ComputerName

AWK

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

BBC BASIC

Works with: BBC BASIC for Windows

      INSTALL @lib$+"SOCKLIB"
      PROC_initsockets
      PRINT "hostname: " FN_gethostname
      PROC_exitsockets

C/C++

Works with: gcc version 4.0.1

Works with: POSIX version .1

#include <stdlib.h>
#include <stdio.h>
#include <limits.h>
#include <unistd.h>
 
int main(void)
{
 char name[_POSIX_HOST_NAME_MAX + 1];
 return gethostname(name, sizeof name) == -1 || printf("%s\n", name) < 0 ? EXIT_FAILURE : EXIT_SUCCESS;
}

C#

System.Net.Dns.GetHostName();

Caché ObjectScript

Write ##class(%SYS.System).GetNodeName()

Clojure

 
(.. java.net.InetAddress getLocalHost getHostName)
 

 
java -cp clojure.jar clojure.main -e "(.. java.net.InetAddress getLocalHost getHostName)"
 

CoffeeScript

 
os = require 'os'
console.log os.hostname()
 

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.

(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"))

Library: CFFI

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

(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))))

BOA> (get-hostname)
"aurora"

D

import std.stdio, std.socket;
 
void main() {
    writeln(Socket.hostName());
}

Delphi

program ShowHostName;
 
{$APPTYPE CONSOLE}
 
uses Windows;
 
var
  lHostName: array[0..255] of char;
  lBufferSize: DWORD;
begin
  lBufferSize := 256;
  if GetComputerName(lHostName, lBufferSize) then
    Writeln(lHostName)
  else
    Writeln('error getting host name');
end.

E

makeCommand("hostname")()[0].trim()

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

F#

printfn "%s" (System.Net.Dns.GetHostName())

Factor

host-name

Forth

Works with: GNU Forth version 0.7.0

include unix/socket.fs
 
hostname type

Erlang

Host = net_adm:localhost().

friendly interactive shell

Translation of: UNIX Shell

hostname

or

uname -n

Fortran

Works with: gfortran

The function/subroutine HOSTNM is a GNU extension.

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

Go

package main
 
import (
	"fmt"
	"os"
)
 
func main() {
	host, _ := os.Hostname()
	fmt.Printf("hostname: %s\n", host)
}

Groovy

println InetAddress.localHost.hostName

Haskell

Library: network

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

Icon and Unicon

procedure main()
  write(&host)
end

IDL

hostname = GETENV('computername')

J

NB. Load the socket libraries
 
  load 'socket'
  coinsert 'jsocket'
 
NB. fetch and implicitly display the hostname
 
  > {: sdgethostname ''
 
NB. If fetching the hostname is the only reason for loading the socket libraries,
NB. and the hostname is fetched only once, then use a 'one-liner' to accomplish it:
 
  > {: sdgethostname coinsert 'jsocket' [ load 'socket'

Java

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

JavaScript

Works with: JScript

var network = new ActiveXObject('WScript.Network');
var hostname = network.computerName;
WScript.echo(hostname);

Lua

Requires: LuaSocket

socket = require "socket"
print( socket.dns.gethostname() )

Liberty BASIC

lpBuffer$=Space$(128) + Chr$(0)
struct SIZE,sz As Long
SIZE.sz.struct=Len(lpBuffer$)
 
calldll #kernel32, "GetComputerNameA",lpBuffer$ as ptr, SIZE as struct, result as Long
CurrentComputerName$=Trim$(Left$(lpBuffer$, SIZE.sz.struct))
 
print CurrentComputerName$

Maple

Sockets:-GetHostName()

Mathematica

$MachineName

MATLAB

This is a built-in MATLAB function. "failed" is a Boolean which will be false if the command sent to the OS succeeds. "hostname" is a string containing the system's hostname, provided that the external command hostname exists.

[failed,hostname] = system('hostname')

mIRC Scripting Language

echo -ag $host

Modula-3

MODULE Hostname EXPORTS Main;
 
IMPORT IO, OSConfig;
 
BEGIN
  IO.Put(OSConfig.HostName() & "\n");
END Hostname.

MUMPS

Write $Piece($System,":")

NetRexx

/* NetRexx */
options replace format comments java crossref savelog symbols binary
 
say InetAddress.getLocalHost.getHostName
 

NewLISP

(! "hostname")

Objective-C

Cocoa / Cocoa Touch / GNUstep:

 
NSLog(@"%@", [[NSProcessInfo processInfo] hostName]);
 

Example Output:

 
2010-09-16 16:20:00.000 Playground[1319:a0f] sierra117.local // Hostname is sierra117.local.
 

Objeck

 
use Net;
 
bundle Default {
  class Hello {
    function : Main(args : String[]) ~ Nil {
      TCPSocket->HostName()->PrintLine();
    }
  }
}
 

OCaml

Unix.gethostname()

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):

uname().nodename

ooRexx

These solutions are platform specific.

Windows Platform

A solution using ActiveX/OLE on Windows

say .oleObject~new('WScript.Network')~computerName

and one using the Windows environment variables

say value('COMPUTERNAME',,'environment')

UNIX Platform

Some UNIX solutions (tested under Mac OS X):

ooRexx (and Rexx) can issue commands directly to the shell it's running under. Output of the shell commands will normally be STDOUT and STDERR. These next two samples will simply output the host name to the console if the program is run from a command prompt.

Note: The address command clause causes the contents of the literal string that follows it to be sent to the command shell.

address command 'hostname -f'

address command "echo $HOSTNAME"

Command output can also be captured by the program to allow further processing. ooRexx provides an external data queue manager (rxqueue) that can be used for this. In the following examples output written to STDOUT/STDERR is piped into rxqueue which sends it in turn to a Rexx queue for further processing by the program:

/* Rexx */
address command "echo $HOSTNAME | rxqueue"
address command "hostname -f | rxqueue"
loop q_ = 1 while queued() > 0
  parse pull hn
  say q_~right(2)':' hn
  end q_
 

A utility class is also provided as a wrapper around the external data queue:

/* Rexx */
qq = .rexxqueue~new()
address command "echo $HOSTNAME | rxqueue"
address command "hostname -f | rxqueue"
loop q_ = 1 while qq~queued() > 0
  hn = qq~pull()
  say q_~right(2)':' hn
  end q_
 

Oz

{System.showInfo {OS.getHostByName 'localhost'}.name}

Pascal

For Windows systems see the Delphi example. On Unix systems, FreePascal has the function GetHostName:

Program HostName;
 
uses
  unix;
 
begin
  writeln('The name of this computer is: ', GetHostName);
end.

Output example on Mac OS X:

The name of this computer is: MyComputer.local

Perl

Works with: Perl version 5.8.6

Library: Sys::HostnameHostname

use Sys::Hostname;
 
$name = hostname;

Perl 6

my $host = qx[hostname];

PHP

echo $_SERVER['HTTP_HOST'];

echo php_uname('n');

Works with: PHP version 5.3+

echo gethostname();

PicoLisp

This will just print the hostname:

(call 'hostname)

To use it as a string in a program:

(in '(hostname) (line T))

Pike

import System;
 
int main(){
   write(gethostname() + "\n");
}

PL/SQL

SET serveroutput ON
BEGIN
  DBMS_OUTPUT.PUT_LINE(UTL_INADDR.GET_HOST_NAME);  
END;

Pop11

lvars host = sys_host_name();

PowerBASIC

This retreives the localhost's name:

HOST NAME TO hostname$

This attempts to retreive the name of an arbitrary machine on the network (assuming ipAddress& is valid):

HOST NAME ipAddress& TO hostname$

PowerShell

Windows systems have the ComputerName environment variable which can be used:

$Env:COMPUTERNAME

Also PowerShell can use .NET classes and methods:

[Net.Dns]::GetHostName()

PureBasic

Works with: PureBasic version 4.41

InitNetwork()
answer$=Hostname()

Python

Works with: Python version 2.5

import socket
host = socket.gethostname()

R

Sys.info provides information about the platform that R is running on. The following code returns the hostname as a string.

Sys.info()[["nodename"]]

Note that Sys.info isn't guaranteed to be available on all platforms. As an alternative, you can call an OS command.

system("hostname", intern = TRUE)

... or retrieve an environment variable

 
env_var <- ifelse(.Platform$OS.type == "windows", "COMPUTERNAME", "HOSTNAME") 
Sys.getenv(env_var)
 

Racket

 
#lang racket/base
(require mzlib/os)
(gethostname)
 

REBOL

print system/network/host

REXX

REGINA and PC/REXX under most MS NT Windows

This REXX solution is for REGINA and PC/REXX under the Microsoft NT family of Windows (XP, Vista, 7, etc).
Other names could be used for the 3rd argument.

say value('COMPUTERNAME',,"ENVIRONMENT")
say value('OS',,"ENVIRONMENT")

output (using Windows/XP)

GERARD46
Windows_NT

R4 and ROO under most MS NT Windows

This REXX solution is for R4 and ROO under the Microsoft NT family of Windows (XP, Vista, 7, etc).
Other names could be used for the 3rd argument.

say value('COMPUTERNAME',,"SYSTEM")
say value('OS',,"SYSTEM")

</lang>

MS DOS (without Windows), userid

Under Microsoft DOS (with no Windows), the closest thing to a name of a host would be the userid.

say userid()

MS DOS (without Windows), version of DOS

But perhaps the name or version of the MS DOS system would be more appropriate than the userid.

'VER'    /*this passes the  VER  command to the MS DOS system. */

Each REXX interpreter has their own name (some have multiple names) for the environmental variables.
Different operating systems may call their hostnames by different identifiers.
IBM mainframes (at one time) called the name of the host as a nodename and it needn't be
specified, in which case an asterisk (*) is returned.
I recall (perhaps wrongly) that Windows/95 and Windows/98 had a different environmental name for the name of the host.

UNIX Solution

This solution is platform specific and uses features that are available to the Regina implementation of Rexx.

Tested with Regina on Mac OS X. Should work on other UNIX/Linux distros.

/* Rexx */
address command "hostname -f" with output stem hn.
do q_ = 1 to hn.0
  say hn.q_
  end q_
exit
 

Ruby

require 'socket'
host = Socket.gethostname

Run BASIC

print Platform$    ' OS where Run BASIC is being hosted
print UserInfo$    ' Information about the user's web browser
print UserAddress$ ' IP address of the user

Scala

println(java.net.InetAddress.getLocalHost.getHostName)

Scheme

Works with: Chicken Scheme

(use posix)
(get-host-name)

Works with: Guile

(gethostname)

Seed7

The library socket.s7i defines the function getHostname, which returns the hostname.

$ include "seed7_05.s7i";
  include "socket.s7i";
 
const proc: main is func
  begin
    writeln(getHostname);
  end func;

Slate

Platform current nodeName

SNOBOL4

 
      output = host(4,"HOSTNAME")
end

Standard ML

NetHostDB.getHostName ()

Smalltalk

Works with: Smalltalk/X

OperatingSystem getHostName

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:

set hname [info hostname]

Toka

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

TUSCRIPT

 
$$ MODE TUSCRIPT
host=HOST ()
 

UNIX Shell

hostname

or

uname -n

Ursala

The user-defined hostname function ignores its argument and returns a string.

#import cli
 
hostname = ~&hmh+ (ask bash)/<>+ <'hostname'>!

For example, the following function returns the square root of its argument if it's running on host kremvax, but otherwise returns the square.

#import flo
 
creative_accounting = (hostname== 'kremvax')?(sqrt,sqr)