Check that file exists

Check that file exists
You are encouraged to solve this task according to the task description, using any language you may know.

In this task, the job is to verify that a file called "input.txt" and the directory called "docs" exist. This should be done twice: once for the current working directory and once for a file and a directory in the filesystem root.

Java

import java.util.File;
public class FileExistsTest {
   public static boolean isFileExists(String filename) {
       boolean exists = new File(filename).exists();
       return exists;
   }
   public static void test(String type, String filename) {
       System.out.println("The following " + type + " called " + filename + 
           (isFileExists(filename) ? " exists." : " not exists.")
       );
   }
   public static void main(String args[]) {
        test("file", "input.txt");
        test("file", File.seperator + "input.txt");
        test("directory", "docs");
        test("directory", File.seperator + "docs" + File.seperator);
   }
}

Perl

  #!/usr/bin/perl
  sub isFileExists($) {
      my ($filename) = @_;
      return -e $filename;
  }
  sub test($$) {
      my ($type, $filename) = @_;
      print "The following " . $type . " called " . $filename . 
          (isFileExists($filename) ? " exists." : " not exists.");
  }
  my $FileSeperator = ($^O eq "MSWin32") ? "\\" : "/";
  test("file", "input.txt");
  test("file", $FileSeperator . "input.txt");
  test("directory", "docs");
  test("directory", $FileSeperator ."docs". $FileSeperator);
  exit;

  # Short version
  my $FileSeperator = ($^O eq "MSWin32") ? "\\" : "/";
  print -e 'input.txt';
  print -e $FileSeperator.'input.txt';
  print -e 'docs';
  print -e $FileSeperator.'docs'.$FileSeperator;

DOS

 if exist input.txt echo The following file called input.txt exists.
 if exist \input.txt echo The following file called \input.txt exists.
 if exist docs echo The following directory called docs exists.
 if exist \docs\ echo The following directory called \docs\ exists.

Tcl

Taking the meaning of the task from the DOS example:

if { [file exists input.txt] } { puts "input.txt exists" } 
if { [file exists [file nativename /input.txt]] } { puts "/input.txt exists" } 

if { [file isdirectory docs] } { puts "docs exists and is a directory" } 
if { [file isdirectory [file nativename /docs]] } { puts "/docs exists and is a directory" }