Hello world/Standard error: Difference between revisions

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=={{header|Ruby}}==
=={{header|Ruby}}==
<lang ruby>$stderr.puts("Goodbye, World!")</lang>
<lang ruby>$stderr.puts("Goodbye, World!")</lang>

=={{header!Slate}}==
<lang slate>inform: 'Goodbye, World!' &resource: DebugConsole.</lang>


=={{header|Standard ML}}==
=={{header|Standard ML}}==

Revision as of 17:56, 5 June 2009

Task
Hello world/Standard error
You are encouraged to solve this task according to the task description, using any language you may know.

A common practice in computing is to send error messages to a different output stream than normal text console messages. The normal messages print to what is called "standard output" or "standard out". The error messages print to "standard error". This separation can be used to redirect error messages to a different place than normal messages.

Show how to print a message to standard error by printing "Goodbye, World!" on that stream.

Ada

<lang ada> with Ada.Text_IO; use Ada.Text_IO;

procedure Goodbye_World is begin

  Put_Line (Standard_Error, "Goodbye, World!");

end Goodbye_World; </lang>

ALGOL 68

The procedures print and printf output to stand out, whereas put and putf can output to any open FILE, including stand error.

Works with: ALGOL 68 version Standard - no extensions to language used
Works with: ALGOL 68G version Any - tested with release mk15-0.8b.fc9.i386
Works with: ELLA ALGOL 68 version Any (with appropriate job cards) - tested with release 1.8.8d.fc9.i386 - note that printf and putf were not ported into ELLA's libraries.
main:(
  put(stand error, ("Goodbye, World!", new line))
)

Output:

Goodbye, World!

C

Unlike puts(), fputs() does not append a terminal newline. <lang c>#include <stdio.h>

int main() { fprintf(stderr, "Goodbye, "); fputs("World!\n", stderr);

return 0; } </lang>

C#

<lang csharp>static class StdErr {

   static void Main(string[] args)
   {
       Console.Error.WriteLine("Goodbye, World!");
   }

}</lang>

C++

<lang cpp>#include <iostream>

using std::cerr; using std::endl;

int main () {

 cerr << "Goodbye, World!" << endl;
 return 0;

}</lang>

Common Lisp

<lang lisp>(format *error-output* "Goodbye, world!~%")</lang>

D

<lang D>import tango.io.Stdout;

void main () {

 Stderr("Goodbye, World!").newline;

}</lang>

E

stderr.println("Goodbye, World!")

Forth

Works with: GNU Forth
outfile-id
  stderr to outfile-id
  ." Goodbye, World!" cr
to outfile-id

Fortran

Normally standard error is associated with the unit 0 but this could be different for different vendors. Therefore since Fortran 2003 there's an intrinsic module which defines the parameter ERROR_UNIT.

<lang fortran>program StdErr

 ! Fortran 2003
 use iso_fortran_env
 ! in case there's no module iso_fortran_env ...
 !integer, parameter :: ERROR_UNIT = 0
 
 write (ERROR_UNIT, *) "Goodbye, World!"

end program StdErr</lang>

Haskell

<lang haskell> import System.IO

hPutStrLn stderr "Goodbye, World!"</lang>

Java

<lang java>public class Err{

  public static void main(String[] args){
     System.err.println("Goodbye, World!");
  }

}</lang>

Metafont

Metafont has no a real way to send a text to the standard output/error nor to a file. Anyway it exists the errmessage command which will output an error message and prompt the user for action (suspending the interpretation of the source).

<lang metafont>errmessage "Error"; message "...going on..."; % if the user decides to go on and not to stop

                         % the program because of the error.</lang>

Modula-3

<lang modula3>MODULE Stderr EXPORTS Main;

IMPORT Wr, Stdio;

BEGIN

 Wr.PutText(Stdio.stderr, "Goodbye, World!\n");

END Stderr.</lang>

Objective-C

Works with: GNUstep
Works with: Cocoa

In Objective-C one can use the standard C library and the stderr as in the C language; nonetheless a common way to output to stderr for logging purpose and/or error notification is the NSLog function, that works almost like fprintf(stderr, "..."), save for the fact that the string is a NSString object.

<lang objc>#import <Foundation/Foundation.h>

int main() {

  fprintf(stderr, "Goodbye, World!\n");
  fputs("Goodbye, World!\n", stderr);
  NSLog(@"Goodbye, World!");
  return 0;

}</lang>

OCaml

<lang ocaml>prerr_endline "Goodbye, World!"; (* this is how you print a string with newline to stderr *) Printf.eprintf "Goodbye, World!\n"; (* this is how you would use printf with stderr *)</lang>

Perl

<lang perl>print STDERR "Goodbye, World!\n";</lang>

PHP

<lang php>fprintf(STDERR, "Goodbye, World!\n");</lang>

Python

Works with: Python version 2.x

<lang python>import sys

print >> sys.stderr, "Goodbye, World!"</lang>

Works with: Python version 3.x

<lang python>import sys

print("Goodbye, World!", file=sys.stderr)</lang>

Ruby

<lang ruby>$stderr.puts("Goodbye, World!")</lang>

Template:Header!Slate

<lang slate>inform: 'Goodbye, World!' &resource: DebugConsole.</lang>

Standard ML

<lang sml>TextIO.output (TextIO.stdErr, "Goodbye, World!\n")</lang>

Tcl

<lang tcl>puts stderr "Goodbye, World!"</lang>

UNIX Shell

echo "Goodbye, World!" > /dev/stderr

UnixPipes

echo "Goodbye, World!" 1>&2