⚠️ Warning: This is a draft ⚠️
This means it might contain formatting issues, incorrect code, conceptual problems, or other severe issues.
If you want to help to improve and eventually enable this page, please fork RosettaGit's repository and open a merge request on GitHub.
{{task|Programming environment operations}} [[Category:Networking and Web Interaction]]
;Task: 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|Any - tested with release mk15-0.8b.fc9.i386}}
{{works with|POSIX|.1}}
STRING hostname;
get(read OF execve child pipe("/bin/hostname","hostname",""), hostname);
print(("hostname: ", hostname, new line))
Aikido
println (System.hostname)
AppleScript
host name of (system info)
AutoHotkey
MsgBox % A_ComputerName
via Windows Management Instrumentation (WMI)
for objItem in ComObjGet("winmgmts:\\.\root\CIMV2").ExecQuery("SELECT * FROM Win32_ComputerSystem")
MsgBox, % "Hostname:`t" objItem.Name
Arc
(system "hostname -f")
AWK
{{noticebox||WARNING: the following purported solution makes an assumption about environment variables that may not be applicable in all circumstances.}}
$ awk 'BEGIN{print ENVIRON["HOST"]}'
E51A08ZD
BaCon
PRINT "Hostname: ", HOSTNAME$
Batch File
Since Windows 2000 :
## BBC BASIC
{{works with|BBC BASIC for Windows}}
```bbcbasic
INSTALL @lib$+"SOCKLIB"
PROC_initsockets
PRINT "hostname: " FN_gethostname
PROC_exitsockets
=={{header|C}}/{{header|C++}}== {{works with|gcc|4.0.1}}
{{works with|POSIX|.1}}
#include <iostream>
#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();
=={{header|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)"
COBOL
identification division.
program-id. hostname.
data division.
working-storage section.
01 hostname pic x(256).
01 nullpos pic 999 value 1.
procedure division.
call "gethostname" using hostname by value length of hostname
string hostname delimited by low-value into hostname
with pointer nullpos
display "Host: " hostname(1 : nullpos - 1)
goback.
end program hostname.
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 ()
#+(or sbcl ccl) (machine-instance)
#+clisp (let ((s (machine-instance))) (subseq s 0 (position #\Space s)))
#-(or sbcl ccl clisp) (error "get-host-name not implemented"))
{{libheader|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))))
(get-hostname)
"aurora"
Crystal
## D
```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. [[Category:E examples needing attention]]
Emacs Lisp
(system-name)
=={{header|F_Sharp|F#}}==
printfn "%s" (System.Net.Dns.GetHostName())
Factor
USE: io.sockets
host-name
Forth
{{works with|GNU Forth|0.7.0}}
include unix/socket.fs
hostname type
Erlang
Host = net_adm:localhost().
friendly interactive shell
{{trans|UNIX Shell}}
or
```fishshell
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
Using fortran 2003 C-interoperability we can call posix C function gethostname (unix system call) directly
program test_hostname
use, intrinsic :: iso_c_binding
implicit none
interface !to function: int gethostname(char *name, size_t namelen);
integer(c_int) function gethostname(name, namelen) bind(c)
use, intrinsic :: iso_c_binding, only: c_char, c_int, c_size_t
integer(c_size_t), value, intent(in) :: namelen
character(len=1,kind=c_char), dimension(namelen), intent(inout) :: name
end function gethostname
end interface
integer(c_int) :: status
integer,parameter :: HOST_NAME_MAX=255
character(kind=c_char,len=1),dimension(HOST_NAME_MAX) :: cstr_hostname
integer(c_size_t) :: lenstr
character(len=:),allocatable :: hostname
lenstr = HOST_NAME_MAX
status = gethostname(cstr_hostname, lenstr)
hostname = c_to_f_string(cstr_hostname)
write(*,*) hostname, len(hostname)
contains
! convert c_string to f_string
pure function c_to_f_string(c_string) result(f_string)
use, intrinsic :: iso_c_binding, only: c_char, c_null_char
character(kind=c_char,len=1), intent(in) :: c_string(:)
character(len=:), allocatable :: f_string
integer i, n
i = 1
do
if (c_string(i) == c_null_char) exit
i = i + 1
end do
n = i - 1 ! exclude c_null_char
allocate(character(len=n) :: f_string)
f_string = transfer(c_string(1:n), f_string)
end function c_to_f_string
end program test_hostname
FreeBASIC
' FB 1.05.0 Win64
' On Windows 10, the command line utility HOSTNAME.EXE prints the 'hostname' to the console.
' We can execute this remotely and read from its 'stdin' stream as follows:
Dim As String hostname
Open Pipe "hostname" For Input As #1
Input #1, hostname
Close #1
Print hostname
Print
Print "Press any key to quit"
Sleep
Gambas
'''[https://gambas-playground.proko.eu/?gist=11d7f489117d7909da509050103b7891 Click this link to run this code]'''
Public Sub Main()
Print System.Host
End
Output:
charlie
Go
Use [https://golang.org/pkg/os/#Hostname os.Hostname
].
package main
import (
"fmt"
"os"
)
func main() {
fmt.Println(os.Hostname())
}
Groovy
## Harbour
```visualfoxpro
? NetName()
Haskell
{{libheader|network}}
import Network.BSD
main = do hostName <- getHostName
putStrLn hostName
Or if you don't want to depend on the network package being installed, you can implement it on your own (this implementation is based on the implementation in the network package).
module GetHostName where
import Foreign.Marshal.Array ( allocaArray0, peekArray0 )
import Foreign.C.Types ( CInt(..), CSize(..) )
import Foreign.C.String ( CString, peekCString )
import Foreign.C.Error ( throwErrnoIfMinus1_ )
getHostName :: IO String
getHostName = do
let size = 256
allocaArray0 size $ \ cstr -> do
throwErrnoIfMinus1_ "getHostName" $ c_gethostname cstr (fromIntegral size)
peekCString cstr
foreign import ccall "gethostname"
c_gethostname :: CString -> CSize -> IO CInt
main = do hostName <- getHostName
putStrLn hostName
=={{header|Icon}} and {{header|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);
jq
Currently jq does not have a "gethostname" or a "system" command, so the best ways for a jq program to have access to the hostname are via an environment variable, or via a command line argument, as illustrated here:
HOST=$(hostname) jq -n --arg hostname $(hostname) '[env.HOST, $hostname]'
{{output}}
[
"mini.local",
"mini.local"
]
Jsish
var hn = exec("hostname", {retAll:true}).data.trim();
Julia
println(gethostname())
{{out}}
harlan
K
_h
{{out}}
`"narasimman-pc"
Kotlin
// version 1.1.4
import java.net.InetAddress
fun main(args: Array<String>) {
println(InetAddress.getLocalHost().hostName)
}
Lasso
This will ge the hostname as reported by the web server
[web_request->httpHost]
-> www.myserver.com
This will ge the hostname as reported by the system OS
define host_name => thread {
data
public initiated::date, // when the thread was initiated. Most likely at Lasso server startup
private hostname::string // as reported by the servers hostname
public onCreate() => {
.reset
}
public reset() => {
if(lasso_version(-lassoplatform) >> 'Win') => {
protect => {
local(process = sys_process('cmd',(:'hostname.exe')))
#process -> wait
.hostname = string(#process -> readstring) -> trim&
#process -> close
}
else
protect => {
local(process = sys_process('/bin/hostname'))
#process -> wait
.hostname = string(#process -> readstring) -> trim&
#process -> close
}
}
.initiated = date(date -> format(`yyyyMMddHHmmss`)) // need to set format to get rid of nasty hidden fractions of seconds
.hostname -> size == 0 ? .hostname = 'undefined'
}
public asString() => .hostname
}
host_name
-> mymachine.local
LFE
(net_adm:localhost)
Liberty BASIC
lpBuffer$=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$
Limbo
As with nearly anything in Inferno, it boils down to reading a file:
implement Hostname;
include "sys.m"; sys: Sys;
include "draw.m";
Hostname: module {
init: fn(nil: ref Draw->Context, nil: list of string);
};
init(nil: ref Draw->Context, nil: list of string)
{
sys = load Sys Sys->PATH;
buf := array[Sys->ATOMICIO] of byte;
fd := sys->open("/dev/sysname", Sys->OREAD);
if(fd == nil)
die("Couldn't open /dev/sysname");
n := sys->read(fd, buf, len buf - 1);
if(n < 1)
die("Couldn't read /dev/sysname");
buf[n++] = byte '\n';
sys->write(sys->fildes(1), buf, n);
}
die(s: string)
{
sys->fprint(sys->fildes(2), "hostname: %s: %r", s);
raise "fail:errors";
}
Sys->ATOMICIO is usually 8 kilobytes; this version truncates if you have a ridiculously long hostname.
Lingo
{{libheader|Shell Xtra}}
sx = xtra("Shell").new()
if the platform contains "win" then
hostname = sx.shell_cmd("hostname", ["eol":RETURN]).line[1] -- win 7 or later
else
hostname = sx.shell_cmd("hostname", RETURN).line[1]
end if
LiveCode
## Lua
Requires: LuaSocket
```lua
socket = require "socket"
print( socket.dns.gethostname() )
M2000 Interpreter
Module Host {
\\ one way
Print computer$
\\ second way
Declare objNetwork "WScript.Network"
With objNetwork, "ComputerName" as cName$
Print cName$, cName$=Computer$
Declare objNetwork Nothing
}
Host
Maple
Sockets:-GetHostName()
=={{header|Mathematica}} / {{header|Wolfram Language}}==
$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
=={{header|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")
Nim
import posix
const size = 64
var s = cstring(newString(size))
discard s.getHostname(size)
echo s
=={{header|Oberon-2}}== Works with oo2c version 2
MODULE HostName;
IMPORT
OS:ProcessParameters,
Out;
BEGIN
Out.Object("Host: " + ProcessParameters.GetEnv("HOSTNAME"));Out.Ln
END HostName.
Output:
Host: localhost.localdomain
=={{header|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 [[Discover the Hostname#MATLAB|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|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}
PARI/GP
Running the hostname
or uname
program and capturing its output (the first line of output) in a string.
str = externstr("hostname")[1];
str = externstr("uname -n")[1];
Pascal
For Windows systems see the [[Hostname#Delphi | 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|5.8.6}}
{{libheader|Sys::Hostname}}
use Sys::Hostname;
$name = hostname;
Perl 6
my $host = qx[hostname];
Phix
constant tmp = "hostname.txt",
cmd = iff(platform()=WINDOWS?"hostname":"uname -n")
{} = system_exec(sprintf("%s > %s",{cmd,tmp}),4)
string host = trim(get_text(tmp))
{} = delete_file("hostname.txt")
?host
{{out}}
"Pete-PC"
PHP
echo $_SERVER['HTTP_HOST'];
echo php_uname('n');
{{works with|PHP|5.3+}}
echo gethostname();
PicoLisp
This will just print the hostname:
(call 'hostname)
To use it as a string in a program:
(in '(hostname) (line T))
Pike
import System;
int main(){
write(gethostname() + "\n");
}
PL/SQL
SET serveroutput on
BEGIN
DBMS_OUTPUT.PUT_LINE(UTL_INADDR.GET_HOST_NAME);
END;
Pop11
lvars host = sys_host_name();
PowerBASIC
This retreives the localhost's name:
HOST NAME TO hostname$
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:
$Env:COMPUTERNAME
Also PowerShell can use .NET classes and methods:
[Net.Dns]::GetHostName()
PureBasic
{{works with|PureBasic|4.41}}
InitNetwork()
answer$=Hostname()
Python
{{works with|Python|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$OS.type == "windows", "COMPUTERNAME", "HOSTNAME")
Sys.getenv(env_var)
Racket
#lang racket/base
(require mzlib/os)
(gethostname)
REBOL
## REXX
### REGINA and PC/REXX under most MS NT Windows
This REXX solution is for REGINA and PC/REXX under the Microsoft NT family of Windows (XP, Vista, 7, etc).
Other names could be used for the 3rd argument.
The ''computername'' is the same as the output for the '''hostname.exe''' program.
```REXX
say value('COMPUTERNAME',,"ENVIRONMENT")
say value('OS',,"ENVIRONMENT")
'''output''' (using Windows/XP)
GERARD46
Windows_NT
R4 and ROO under most MS NT Windows
This REXX solution is for R4 and ROO under the Microsoft NT family of Windows (XP, Vista, 7, etc).
Other names could be used for the 3rd argument.
say value('COMPUTERNAME',,"SYSTEM")
say value('OS',,"SYSTEM")
===MS DOS (without Windows), userid=== Under Microsoft DOS (with no Windows), the closest thing to a name of a host would be the userid.
say userid()
===MS DOS (without Windows), version of DOS=== But perhaps the name or version of the MS DOS system would be more appropriate than the userid.
'VER' /*this passes the VER command to the MS DOS system. */
Each REXX interpreter has their own name (some have multiple names) for the environmental variables.
Different operating systems may call their hostnames by different identifiers.
IBM mainframes (at one time) called the name of the host as a ''nodename'' and it needn't be
specified, in which case an asterisk (*) is returned.
I recall (perhaps wrongly) that Windows/95 and Windows/98 had a different environmental name for the name of the host.
UNIX Solution
This solution is platform specific and uses features that are available to the Regina implementation of Rexx. :Tested with Regina on Mac OS X. Should work on other UNIX/Linux distros.
/* Rexx */
address command "hostname -f" with output stem hn.
do q_ = 1 to hn.0
say hn.q_
end q_
exit
Ruby
require 'socket'
host = Socket.gethostname
Run BASIC
print Platform$ ' OS where Run BASIC is being hosted
print UserInfo$ ' Information about the user's web browser
print UserAddress$ ' IP address of the user
Rust
Works on windows and linux with crate hostname
version 0.1.5
fn main() {
match hostname::get_hostname() {
Some(host) => println!("hostname: {}", host),
None => eprintln!("Could not get hostname!"),
}
}
Scala
println(java.net.InetAddress.getLocalHost.getHostName)
Scheme
{{works with|Chicken Scheme}}
(use posix)
(get-host-name)
{{works with|Guile}}
(gethostname)
Seed7
The library [http://seed7.sourceforge.net/libraries/socket.htm socket.s7i] defines the function [http://seed7.sourceforge.net/libraries/socket.htm#getHostname getHostname], which returns the hostname.
$ include "seed7_05.s7i";
include "socket.s7i";
const proc: main is func
begin
writeln(getHostname);
end func;
Sidef
var sys = frequire('Sys::Hostname');
var host = sys.hostname;
Or:
var host = `hostname`.chomp;
Slate
## SNOBOL4
```snobol4
output = host(4,"HOSTNAME")
end
Standard ML
NetHostDB.getHostName ()
Smalltalk
{{works with|Smalltalk/X}}
## SQL
{{works with|Oracle}}
```sql
select host_name from v$instance;
SQL PL
{{works with|Db2 LUW}}
SELECT HOST_NAME FROM SYSIBMADM.ENV_SYS_INFO
Output:
HOST_NAME
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
hostname
1 record(s) selected.
Swift
Swift 3
print(ProcessInfo.processInfo.hostName)
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
or
```bash
uname -n
Ursa
out (ursa.net.localhost.name) endl console
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)
VBScript
Set objNetwork = CreateObject("WScript.Network")
WScript.Echo objNetwork.ComputerName
Vim Script
echo hostname()
Visual Basic
{{works with|Visual Basic|5}} {{works with|Visual Basic|6}} {{works with|VBA|Access 97}} {{works with|VBA|6.5}} {{works with|VBA|7.1}}
Option Explicit
Private Declare Function GetComputerName Lib "kernel32.dll" Alias "GetComputerNameW" _
(ByVal lpBuffer As Long, ByRef nSize As Long) As Long
Private Const MAX_COMPUTERNAME_LENGTH As Long = 31
Private Const NO_ERR As Long = 0
Private Function Hostname() As String
Dim i As Long, l As Long, s As String
s = Space$(MAX_COMPUTERNAME_LENGTH)
l = Len(s) + 1
i = GetComputerName(StrPtr(s), l)
Debug.Assert i <> 0
Debug.Assert l <> 0
Hostname = Left$(s, l)
End Function
Sub Main()
Debug.Assert Hostname() = Environ$("COMPUTERNAME")
End Sub
zkl
Or open a server socket, which contains the hostname.
```zkl
Network.TCPServerSocket.open(8080).hostname
{{omit from|ACL2}} {{omit from|Locomotive Basic|Does not have a hostname.}} {{omit from|ML/I}} {{omit from|PARI/GP}} {{omit from|TI-83 BASIC}} {{omit from|TI-89 BASIC}} {{omit from|Unlambda|Does not have network access.}} {{omit from|ZX Spectrum Basic|Does not have a hostname.}} {{omit from|Commodore BASIC}}