Delete a file: Difference between revisions

From Rosetta Code
Content added Content deleted
(added factor implementation)
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<file:///input.txt>.delete(null)
<file:///input.txt>.delete(null)
<file:///docs>.delete(null)</lang>
<file:///docs>.delete(null)</lang>

=={{header|Factor}}==
<lang factor>"docs" "/docs" [ delete-tree ] bi@
"input.txt" "/input.txt" [ delete-file ] bi@</lang>


=={{header|Forth}}==
=={{header|Forth}}==

Revision as of 12:22, 25 December 2009

Task
Delete a file
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 delete a file called "input.txt" and delete a directory called "docs". This should be done twice: once "here", i.e. in the current working directory and once in the filesystem root.

Ada

<lang ada>with Ada.Directories; use Ada.Directories;</lang> and then <lang ada>Delete_File ("input.txt"); Delete_File ("/input.txt"); Delete_Tree ("docs"); Delete_Tree ("/docs");</lang> Naming conventions for the file path are OS-specific. The language does not specify the encoding of the file paths, the directory separators or brackets, the file extension delimiter, the file version delimiter and syntax. The example provided works under Linux and Windows.

ALGOL 68

Note: scratch does not appear to do anything on ALGOL 68G. Also note that file names are Operating System dependent. <lang algol68>main:(

 PROC remove = (STRING file name)INT: 
 BEGIN
   FILE actual file;
   INT errno = open(actual file, file name, stand back channel);
   IF errno NE 0 THEN stop remove FI;
   scratch(actual file); # detach the book and burn it #
   errno
 EXIT
 stop remove:
     errno
 END;
 remove("input.txt");
 remove("/input.txt");
 remove("docs");
 remove("/docs")

)</lang>

AutoHotkey

<lang AutoHotkey>FileDelete, input.txt FileDelete, \input.txt FileRemoveDir, docs, 1 FileRemoveDir, \docs, 1</lang>

AWK

Assuming we are on a Unix/Linux or at least Cygwin system: <lang awk>system("rm input.txt"); system("rm /input.txt"); system("rm -rf docs"); system("rm -rf /docs");</lang>

C

ISO C: <lang c>#include <stdio.h>

int main() {

 remove("input.txt");
 remove("/input.txt");
 remove("docs");
 remove("/docs");
 return 0;

}</lang>

POSIX: <lang c>#include <unistd.h>

int main() {

 unlink("input.txt");
 unlink("/input.txt");
 rmdir("docs");
 rmdir("/docs");
 return 0;

}</lang>

C++

<lang cpp>#include <cstdio>

  1. include <direct.h>

int main() { remove( "input.txt" ); remove( "/input.txt" ); _rmdir( "docs" ); _rmdir( "/docs" );

return 0; }</lang>

C#

<lang csharp>using System; using System.IO;

namespace RosettaCode {

   class Program {
       static void Main() {
           try {
               File.Delete("input.txt");
               Directory.Delete("docs");
               File.Delete(@"\input.txt");
               Directory.Delete(@"\docs");
           } catch (Exception exception) {
               Console.WriteLine(exception.Message);
           }
       }
   }

}</lang>

Clojure

<lang lisp>(import '(java.io File)) (.delete (File. "output.txt")) (.delete (File. "docs"))

(.delete (new File (str (File/separator) "output.txt"))) (.delete (new File (str (File/separator) "docs")))</lang>

Common Lisp

<lang lisp>(delete-file (make-pathname :name "input.txt")) (delete-file (make-pathname :directory '(:absolute "") :name "input.txt"))</lang> To delete directories we need an implementation specific extension. In clisp this is ext:delete-dir.

Works with: CLISP

<lang lisp>(let ((path (make-pathname :directory '(:relative "docs"))))

 (ext:delete-dir path))

(let ((path (make-pathname :directory '(:absolute "docs"))))

 (ext:delete-dir path))</lang>

Or you can use the portability library CL-FAD:

Library: CL-FAD

<lang lisp>(let ((path (make-pathname :directory '(:relative "docs"))))

 (cl-fad:delete-directory-and-files path))</lang>

D

Library: Tango

<lang d>import tango.io.Path;

void main() {

   remove("input.txt");
   remove("/input.txt");
   remove("docs");
   remove("/docs");

}</lang>

Library: Tango

POSIX: <lang d>import tango.stdc.posix.unistd;

void main() {

 unlink("input.txt");
 unlink("/input.txt");
 rmdir("docs");
 rmdir("/docs");

}</lang>

E

<lang e><file:input.txt>.delete(null) <file:docs>.delete(null) <file:///input.txt>.delete(null) <file:///docs>.delete(null)</lang>

Factor

<lang factor>"docs" "/docs" [ delete-tree ] bi@ "input.txt" "/input.txt" [ delete-file ] bi@</lang>

Forth

There is no means to delete directories in ANS Forth. <lang forth> s" input.txt" delete-file throw s" /input.txt" delete-file throw</lang>

Fortran

Works with: Fortran version 90 and later

I don't know a way of deleting directories in Fortran <lang fortran>OPEN (UNIT=5, FILE="input.txt", STATUS="OLD")  ! Current directory CLOSE (UNIT=5, STATUS="DELETE") OPEN (UNIT=5, FILE="/input.txt", STATUS="OLD")  ! Root directory CLOSE (UNIT=5, STATUS="DELETE")</lang>

Haskell

<lang haskell>import System.IO import System.Directory

main = do

 removeFile "output.txt"
 removeDirectory "docs"
 removeFile "/output.txt"
 removeDirectory "/docs"</lang>

Io

<lang io>Directory fileNamed("input.txt") remove Directory directoryNamed("docs") remove RootDir := Directory clone setPath("/") RootDir fileNamed("input.txt") remove RootDir directoryNamed("docs") remove</lang>

J

The J standard library comes with a set of file access utilities. <lang j> load 'files'

  ferase 'input.txt'
  ferase '\input.txt'
  ferase 'docs'
  ferase '\docs'

NB. Or all at once...

  ferase 'input.txt';'/input.txt';'docs';'/docs'</lang>

The function above actually uses a foreign conjunction and defined in the files library like so: <lang j>NB. ========================================================= NB.*ferase v erases a file NB. Returns 1 if successful, otherwise _1 ferase=: (1!:55 :: _1:) @ (fboxname &>) @ boxopen</lang>

This means that you can directly erase files and directories without loading the files library. <lang j>1!:55 <'input.txt' 1!:55 <'\input.txt' 1!:55 <'docs' 1!:55 <'\docs'</lang>

Java

<lang java>import java.util.File; public class FileDeleteTest {

  public static boolean deleteFile(String filename) {
      boolean exists = new File(filename).delete();
      return exists;
  }
  public static void test(String type, String filename) {
      System.out.println("The following " + type + " called " + filename + 
          (deleteFile(filename) ? " was deleted." : " could not be deleted.")
      );
  }
  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);
  }

}</lang>

JavaScript

Works with: JScript

<lang javascript>var fso = new ActiveXObject("Scripting.FileSystemObject");

fso.DeleteFile('input.txt'); fso.DeleteFile('c:/input.txt');

fso.DeleteFolder('docs'); fso.DeleteFolder('c:/docs');</lang>

or

<lang javascript>var fso = new ActiveXObject("Scripting.FileSystemObject"); var f; f = fso.GetFile('input.txt'); f.Delete(); f = fso.GetFile('c:/input.txt'); f.Delete(); f = fso.GetFolder('docs'); f.Delete(); f = fso.GetFolder('c:/docs'); f.Delete();</lang>

Works with: UCB Logo

UCB Logo has no means to delete directories. <lang logo>erasefile "input.txt erasefile "/input.txt</lang>

MAXScript

There's no way to delete folders in MAXScript <lang maxscript>-- Here deleteFile "input.txt" -- Root deleteFile "\input.txt"</lang>

Objective-C

<lang objc>NSFileManager *fm = [NSFileManager defaultManager];

[fm removeFileAtPath:@"input.txt" handler:nil]; [fm removeFileAtPath:@"docs" handler:nil];</lang>

OCaml

<lang ocaml>Sys.remove "input.txt";; Sys.remove "/input.txt";;</lang>

with the Unix library: <lang ocaml>#load "unix.cma";; Unix.unlink "input.txt";; Unix.unlink "/input.txt";; Unix.rmdir "docs";; Unix.rmdir "/docs";;</lang>

Oz

<lang oz>for Dir in ["/" "./"] do

  try {OS.unlink Dir#"output.txt"}
  catch _ then {System.showInfo "File does not exist."} end
  try {OS.rmDir Dir#"docs"}
  catch _ then {System.showInfo "Directory does not exist."} end

end</lang>

Perl

<lang perl>use File::Spec::Functions qw(catfile rootdir);

  1. here

unlink 'input.txt'; rmdir 'docs';

  1. root dir

unlink catfile rootdir, 'input.txt'; rmdir catfile rootdir, 'docs';</lang>

Without Perl Modules

Current directory

perl -e 'unlink input.txt'
perl -e 'rmdir docs'

Root Directory

perl -e 'unlink "/input.txt"'
perl -e 'rmdir "/docs"'

PHP

<lang php><?php unlink('input.txt'); unlink('/input.txt'); rmdir('docs'); rmdir('/docs'); ?></lang>

Pike

<lang pike>int main(){

  rm("input.txt");
  rm("/input.txt");
  rm("docs");
  rm("/docs");

}</lang>

PowerShell

<lang powershell># possible aliases for Remove-Item: rm, del, ri Remove-Item input.txt Remove-Item \input.txt # file system root

Remove-Item -Recurse docs # recurse for deleting folders including content Remove-Item -Recurse \docs</lang>

Python

<lang python>import os

  1. current directory

os.remove("output.txt") os.rmdir("docs")

  1. root directory

os.remove("/output.txt") os.rmdir("/docs")</lang> If you wanted to remove a directory and all its contents, recursively, you would do: <lang python>import shutil shutil.rmtree("docs")</lang>

R

<lang R>file.remove("input.txt") file.remove("/input.txt")

  1. or

file.remove("input.txt", "/input.txt")

  1. or

unlink("input.txt"); unlink("/input.txt")

  1. directories needs the recursive flag

unlink("docs", recursive = TRUE) unlink("/docs", recursive = TRUE)</lang>

The function unlink allows wildcards (* and ?)

Raven

<lang raven>'input.txt' delete '/input.txt' delete 'docs' rmdir '/docs' rmdir</lang>

REBOL

<lang REBOL>; Local. delete %input.txt delete-dir %docs/

Root.

delete %/input.txt delete-dir %/docs/</lang>

Ruby

<lang ruby>File.delete("output.txt", "/output.txt") Dir.delete("docs") Dir.delete("/docs")</lang>

Scheme

Works with: Scheme version R6RS

[1]

<lang scheme>(delete-file filename)</lang>

Slate

(It will succeed deleting the directory if it is empty)

<lang slate>(File newNamed: 'input.txt') delete. (File newNamed: '/input.txt') delete. (Directory newNamed: 'docs') delete. (Directory newNamed: '/docs') delete.</lang>

Smalltalk

(It will succeed deleting the directory if it is empty)

<lang smalltalk>File remove: 'input.txt'. File remove: 'docs'. File remove: '/input.txt'. File remove: '/docs'</lang>

Standard ML

<lang sml>OS.FileSys.remove "input.txt"; OS.FileSys.remove "/input.txt"; OS.FileSys.rmDir "docs"; OS.FileSys.rmDir "/docs";</lang>

Tcl

<lang tcl>file delete input.txt /input.txt

  1. preserve directory if non-empty

file delete docs /docs

  1. delete even if non-empty

file delete -force docs /docs</lang>

Toka

<lang toka>needs shell " docs" remove " input.txt" remove</lang>

UNIX Shell

<lang bash>rm -rf docs rm input.txt rm -rf /docs rm /input.txt</lang>

Vedit macro language

Vedit allows using either '\' or '/' as directory separator character, it is automatically converted to the one used by the operating system. <lang vedit>// In current directory File_Delete("input.txt", OK) File_Rmdir("docs")

// In the root directory File_Delete("/input.txt", OK) File_Rmdir("/docs")</lang>

Visual Basic .NET

Platform: .NET

Works with: Visual Basic .NET version 9.0+

<lang vbnet>'Current Directory IO.Directory.Delete("docs") IO.Directory.Delete("docs", True) 'also delete files and sub-directories IO.File.Delete("output.txt")

'Root IO.Directory.Delete("\docs") IO.File.Delete("\output.txt")

'Root, platform independent IO.Directory.Delete(IO.Path.DirectorySeparatorChar & "docs") IO.File.Delete(IO.Path.DirectorySeparatorChar & "output.txt")</lang>