Hostname

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Task
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.

Contents

[edit] 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;

[edit] 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))

[edit] Aikido

 
println (System.hostname)
 

[edit] AutoHotkey

MsgBox % A_ComputerName

[edit] AWK

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

[edit] C/C++

Works with: gcc version 4.0.1

Works with: POSIX version .1 

#include <limits.h>
#include <unistd.h>
 
int main()
{
    char name[_POSIX_HOST_NAME_MAX+1];
    gethostname(name, _POSIX_HOST_NAME_MAX+1);
    return 0;
}

[edit] C#

System.Net.Dns.GetHostName();

[edit] Clojure

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

[edit] 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"

[edit] D

import std.stdio;
import std.socket;
 
void main()
{
    writefln("%s", Socket.hostName());
}

[edit] 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.

[edit] Factor

host-name

[edit] Forth

Works with: GNU Forth version 0.7.0 

include unix/socket.fs
 
hostname type

[edit] 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

[edit] Go

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

[edit] Groovy

println InetAddress.localHost.hostName

[edit] Haskell

Library: network 

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

[edit] Icon and Unicon

[edit] Icon

procedure main()
  write(&host)
end

[edit] Unicon

This Icon solution works in Unicon.

[edit] IDL

hostname = GETENV('computername')

[edit] 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'

[edit] 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.
        }
    }
}

[edit] JavaScript

Works with: JScript 

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

[edit] 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
nSize=SIZE.sz.struct
CurrentComputerName$=Trim$(Left$(lpBuffer$, SIZE.sz.struct))
 
print CurrentComputerName$

[edit] Mathematica

$MachineName

[edit] 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')

[edit] Modula-3

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

[edit] MUMPS

 
Write $System
 
The output varies by implementation. The following is an example of Intersystem's Caché 5.2.0.329.0:
USER>Write $SYSTEM
STORMSTATION:CACHE520

The portion before the colon is the machine running Caché, and the portion after the colon is the instance.

[edit] Objective-C

NSLog(@"%@", [[NSHost currentHost] name]);

(does not work on iPhone)

[edit] Objeck

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

[edit] OCaml

Unix.gethostname()

[edit] 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

[edit] Oz

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

[edit] Perl

Works with: Perl version 5.8.6

Library: Sys::HostnameHostname 

use Sys::Hostname;
 
$name = hostname;

[edit] PHP

echo $_SERVER['HTTP_HOST'];
echo php_uname('n');

Works with: PHP version 5.3+ 

echo gethostname();

[edit] PicoLisp

This will just print the hostname: 

(call 'hostname)

To use it as a string in a program: 

(in '(hostname) (line T))

[edit] Pike

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

[edit] PL/SQL

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

[edit] Pop11

lvars host = sys_host_name();

[edit] 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$

[edit] 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()

[edit] PureBasic

Works with: PureBasic version 4.41 

InitNetwork()
answer$=Hostname()

[edit] Python

Works with: Python version 2.5 

import socket
host = socket.gethostname()

[edit] 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)
 

[edit] REBOL

print system/network/host

[edit] Ruby

require 'socket'
host = Socket.gethostname

[edit] Scala

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

[edit] Scheme

Works with: Chicken Scheme 

(use posix)
(get-host-name)

[edit] Slate

Platform current nodeName

[edit] SNOBOL4

 
      output = host(4,"HOSTNAME")
end

[edit] Standard ML

NetHostDB.getHostName ()

[edit] 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]

[edit] Toka

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

[edit] UNIX Shell

hostname

or 

uname -n

[edit] 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)
Retrieved from "http://rosettacode.org/wiki/Hostname"
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