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.
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.WritleLine("Goodbye, World!");
}
}</lang>
C++
<lang cpp>#include <iostream>
using std::cerr; using std::endl;
int main () {
cerr << "Goodbye, World!" << endl;
return 0;
}</lang>
E
stderr.println("Goodbye, World!")
Forth
outfile-id stderr to outfile-id ." Goodbye, World!" cr to outfile-id
Haskell
import System.IO hPutStrLn stderr "Goodbye, World!"
Java
<lang java>public class Err{
public static void main(String[] args){
System.err.println("Goodbye, World!");
}
}</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
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
<lang python>import sys
print >> sys.stderr, "Goodbye, World!"</lang>
<lang python>import sys
print("Goodbye, World!", file=sys.stderr)</lang>
Ruby
<lang ruby>$stderr.puts("Goodbye, World!")</lang>
UNIX Shell
echo "Goodbye, World!" > /dev/stderr