Create a file: Difference between revisions

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m (→‎[[#ALGOL 68]]: fix code)
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s" output.txt" w/o create-file throw ( fileid) drop
s" output.txt" w/o create-file throw ( fileid) drop
s" /output.txt" w/o create-file throw ( fileid) drop
s" /output.txt" w/o create-file throw ( fileid) drop

=={{header|Fortran}}==
{{works with|Fortran|90 and later}}
Don't know a way of creating directories in Fortran
OPEN (UNIT=5, FILE="output.txt", STATUS="NEW") ! Current directory
CLOSE (UNIT=5)
OPEN (UNIT=5, FILE="/output.txt", STATUS="NEW") ! Root directory
CLOSE (UNIT=5)


=={{header|Haskell}}==
=={{header|Haskell}}==

Revision as of 15:57, 21 October 2008

Task
Create 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 create a new empty file called "output.txt" of size 0 byte and an empty directory called "docs". This should be done twice: once "here", i.e. in the current working directory and once in the filesystem root.

ALGOL 68

Note: file names are Operating System dependent. ALGOL 68G does not support pages. It may be best to to use an operating system provided library.

main:(
  PROC touch = (STRING file name)INT:  
  BEGIN
    FILE actual file;
    INT errno = open(actual file, file name, stand out channel);
    IF errno NE 0 THEN stop touch FI;
    close(actual file); # detach the book and keep it #
    errno
  EXIT
  stop touch:
      errno
  END;

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

  # ALGOL 68 has no concept of directories, 
    however a file can have multiple pages, 
    the pages are identified by page number only */

  PROC mkpage(STRING file name, INT page x)INT:
  BEGIN
    FILE actual file;
    INT errno = open(actual file, file name, stand out channel);
    IF errno NE 0 THEN stop touch FI;
    set(actual file,page x,1,1); # skip to page x, line 1, character 1 #
    close(actual file); # detach the new page and keep it #
    errno
  EXIT
  stop mkpage:
      errno
  END;

  mkpage("input.txt",2);
)

D

For file creation, std.file.write function & std.stream.file class are used.
For dir creation, std.file.mkdir is used.

module fileio ;
import std.stdio ;
import std.path ;
import std.file ;
import std.stream ;

string[] genName(string name){
  string cwd  = curdir ~ sep ; // on current directory
  string root = sep ;          // on root 
  name = std.path.getBaseName(name) ;  
  return [cwd ~ name, root ~ name] ;
}
void Remove(string target){
  if(exists(target)){
    if (isfile(target)) 
      std.file.remove(target);
    else
      std.file.rmdir(target) ;
  }
}
void testCreate(string filename, string dirname){
  // files:
  foreach(fn ; genName(filename))
    try{
      writefln("file to be created : %s", fn) ;
      std.file.write(fn, cast(void[])null) ; 
      writefln("\tsuccess by std.file.write") ; Remove(fn) ;
      (new std.stream.File(fn, FileMode.OutNew)).close() ; 
      writefln("\tsuccess by std.stream") ; Remove(fn) ;
    } catch(Exception e) {
      writefln(e.msg) ;
    }
  // dirs:
  foreach(dn ; genName(dirname))
    try{
      writefln("dir to be created : %s", dn) ;
      std.file.mkdir(dn) ; 
      writefln("\tsuccess by std.file.mkdir") ; Remove(dn) ;
    } catch(Exception e) {
      writefln(e.msg) ;
    }
}
void main(){
  writefln("== test: File & Dir Creation ==") ;
  testCreate("output.txt", "docs") ;
}

DOS Batch File

 md docs
 md \docs

Forth

There is no means to create directories in ANS Forth.

 s" output.txt" w/o create-file throw ( fileid) drop
s" /output.txt" w/o create-file throw ( fileid) drop

Fortran

Works with: Fortran version 90 and later

Don't know a way of creating directories in Fortran

OPEN (UNIT=5, FILE="output.txt", STATUS="NEW")   ! Current directory
CLOSE (UNIT=5)
OPEN (UNIT=5, FILE="/output.txt", STATUS="NEW")  ! Root directory
CLOSE (UNIT=5)

Haskell

import System.IO
import System.Directory

createFile name = do
  h <- openFile name WriteMode
  hClose h

main = do
  createFile "output.txt"
  createDirectory "docs"
  createFile "/output.txt"
  createDirectory "/docs"

Java

import java.util.File;
public class CreateFileTest {
   public static String createNewFile(String filename) {
       try {
           // Create file if it does not exist
           boolean success = new File(filename).createNewFile();
           if (success) {
               return " did not exist and was created successfully.";
           } else {
               return " already exists.";
           }
       } catch (IOException e) {
               return " could not be created.";
       }
   }
   public static void test(String type, String filename) {
       System.out.println("The following " + type + " called " + filename + 
           createNewFile(filename)
       );
   }
   public static void main(String args[]) {
        test("file", "output.txt");
        test("file", File.seperator + "output.txt");
        test("directory", "docs");
        test("directory", File.seperator + "docs" + File.seperator);
   }
}

MAXScript

-- Here
f = createFile "output.txt"
close f
makeDir (sysInfo.currentDir + "\docs")
-- System root
f = createFile "\output.txt"
close f
makeDir ("c:\docs")

OCaml

<ocaml># let oc = open_out "output.txt" in

 close_out oc;;

- : unit = ()

  1. Unix.mkdir "docs" 0o750 ;; (* rigths 0o750 for rwxr-x--- *)

- : unit = ()</ocaml>

(for creation in the filesystem root, replace the filenames by "/output.txt" and "/docs")

Perl

use File::Spec::Functions qw(catfile rootdir);
{ # here
    open my $fh, '>', 'output.txt';
    mkdir 'docs';
};
{ # root dir
    open my $fh, '>', catfile rootdir, 'output.txt';
    mkdir catfile rootdir, 'docs';
};

Without Perl Modules

Current directory

perl -e 'qx(touch output.txt)'
perl -e 'mkdir docs'

Root directory

perl -e 'qx(touch /output.txt)'
perl -e 'mkdir "/docs"'

Python

Current directory

import os
f = open("output.txt", "w")
f.close()
os.mkdir("docs")

Root directory

f = open("/output.txt", "w")
f.close()
os.mkdir("/docs")
Works with: Python version 2.5

Exception-safe way to create file:

from __future__ import with_statement
import os
def create(dir):
    with open(os.path.join(dir, "output.txt"), "w"):
        pass
    os.mkdir(os.path.join(dir, "docs"))
   
create(".") # current directory
create("/") # root directory

Tested on Windows. It should work on Linux and possibly on Mac OS X

Raven

"" as str
str 'output.txt'  write
str '/output.txt' write
'docs'  mkdir
'/docs' mkdir

Smalltalk

Squeak has no notion of 'current directory' because it isn't tied to the shell that created it.

 (FileDirectory on: 'c:\') newFileNamed: 'output.txt'; createDirectory: 'docs'.

In GNU Smalltalk you can do instead:

 ws := (File name: 'output.txt') writeStream.
 ws close.
 Directory create: 'docs'.

 ws := (File name: '/output.txt') writeStream.
 ws close.
 Directory create: '/docs'.

Tcl

Assuming that we're supposed to create two files and two directories (one each here and one each in the file system root) and further assuming that the code is supposed to be portable, i.e. work on win, linux, MacOS (the task is really not clear):

close [open output.txt w] 
close [open [file nativename /output.txt] w] 

file mkdir docs
file mkdir [file nativename /docs]

Toka

 needs shell
 " output.txt" "W" file.open file.close
 " /output.txt" "W" file.open file.close

 ( Create the directories with permissions set to 777)
 " docs" &777 mkdir
 " /docs" &777 mkdir

Visual Basic .NET

Platform: .NET

Works with: Visual Basic .NET version 9.0+
'Current Directory
IO.Directory.CreateDirectory("docs")
IO.File.Create("output.txt").Close()

 'Root
IO.Directory.CreateDirectory("\docs")
IO.File.Create("\output.txt").Close()

 'Root, platform independent
IO.Directory.CreateDirectory(IO.Path.DirectorySeparatorChar & "docs")
IO.File.Create(IO.Path.DirectorySeparatorChar & "output.txt").Close()

UNIX Shell

 touch output.txt
 touch /output.txt
 mkdir docs
 mkdir /docs