Write entire file: Difference between revisions

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Revision as of 11:48, 5 September 2021

Task

(Over)write a file so that it contains a string.

The reverse of Read entire file—for when you want to update or create a file which you would read in its entirety all at once.

11l

<lang 11l>File(filename, ‘w’).write(string)</lang>

AArch64 Assembly

Works with: as version Raspberry Pi 3B version Buster 64 bits

<lang AArch64 Assembly> /* ARM assembly AARCH64 Raspberry PI 3B */ /* program writeFile64.s */

/*******************************************/ /* Constantes file */ /*******************************************/ /* for this file see task include a file in language AArch64 assembly*/ .include "../includeConstantesARM64.inc"

/*********************************/ /* Initialized data */ /*********************************/ .data szMessErreur: .asciz "Error open file.\n" szMessErreur1: .asciz "Error close file.\n" szMessErreur2: .asciz "Error write file.\n" szMessWriteOK: .asciz "String write in file OK.\n"

szParamNom: .asciz "./fic1.txt" // file name sZoneEcrit: .ascii "(Over)write a file so that it contains a string."

              .equ LGZONEECRIT, . - sZoneEcrit

/*********************************/ /* UnInitialized data */ /*********************************/ .bss

/*********************************/ /* code section */ /*********************************/ .text .global main main: // entry of program

                             // file open
   mov x0,AT_FDCWD           // current directory
   ldr x1,qAdrszParamNom     // filename
   mov x2,O_CREAT|O_WRONLY   //  flags
   ldr x3,oficmask1          // mode
   mov x8,OPEN               // Linux call system
   svc 0                     //
   cmp x0,0                  // error ?
   ble erreur                // yes
   mov x28,x0                // save File Descriptor
                             // x0 = FD
   ldr x1,qAdrsZoneEcrit     // write string address
   mov x2,LGZONEECRIT        // string size
   mov x8,WRITE              // Linux call system
   svc 0 
   cmp x0,0                 // error ?
   ble erreur2               // yes
                             // close file
   mov x0,x28                // File Descriptor
   mov x8,CLOSE              // Linuc call system
   svc 0 
   cmp x0,0                  // error ?
   blt erreur1
   ldr x0,qAdrszMessWriteOK
   bl affichageMess 
   mov x0,#0                 // return code OK
   b 100f

erreur:

   ldr x1,qAdrszMessErreur
   bl affichageMess          // display error message
   mov x0,#1
   b 100f

erreur1:

   ldr x1,qAdrszMessErreur1  // x0 <- adresse chaine 
   bl affichageMess          // display error message
   mov x0,#1                 // return code error
   b 100f

erreur2:

   ldr x0,qAdrszMessErreur2
   bl affichageMess          // display error message
   mov x0,#1                 // return code error
   b 100f

100: // program end

   mov x8,EXIT
   svc #0

qAdrszParamNom: .quad szParamNom qAdrszMessErreur: .quad szMessErreur qAdrszMessErreur1: .quad szMessErreur1 qAdrszMessErreur2: .quad szMessErreur2 qAdrszMessWriteOK: .quad szMessWriteOK qAdrsZoneEcrit: .quad sZoneEcrit oficmask1: .quad 0644 // this zone is Octal number (0 before) /********************************************************/ /* File Include fonctions */ /********************************************************/ /* for this file see task include a file in language AArch64 assembly */ .include "../includeARM64.inc"

</lang>

Ada

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

procedure Write_Whole_File is

  File_Name : constant String := "the_file.txt";

  F : File_Type;

begin

  begin
     Open (F, Mode => Out_File, Name => File_Name);
  exception
     when Name_Error => Create (F, Mode => Out_File, Name => File_Name);
  end;

  Put (F, "(Over)write a file so that it contains a string. "               &
          "The reverse of Read entire file—for when you want to update or " &
          "create a file which you would read in its entirety all at once.");
  Close (F);

end Write_Whole_File; </lang>

ALGOL 68

<lang algol68>IF FILE output;

   STRING output file name = "output.txt";
   open( output, output file name, stand out channel ) = 0

THEN

   # file opened OK #
   put( output, ( "line 1", newline, "line 2", newline ) );
   close( output )

ELSE

   # unable to open the output file #    
   print( ( "Cannot open ", output file name, newline ) )

FI</lang>

Arturo

<lang rebol>contents: "Hello World!" write "output.txt" contents</lang>

AutoHotkey

<lang AutoHotkey>file := FileOpen("test.txt", "w") file.Write("this is a test string") file.Close()</lang>

AWK

syntax: GAWK -f WRITE_ENTIRE_FILE.AWK

BEGIN {

   dev = "FILENAME.TXT"
   print("(Over)write a file so that it contains a string.") >dev
   close(dev)
   exit(0)

} </lang>

BaCon

String: <lang freebasic>SAVE s$ TO filename$</lang>

Binary: <lang freebasic>BSAVE mem TO filename$ SIZE n</lang>

BBC BASIC

<lang bbcbasic>file% = OPENOUT filename$ PRINT#file%, text$ CLOSE#file%</lang>

Bracmat

<lang bracmat>put$("(Over)write a file so that it contains a string.",file,NEW)</lang>

C

Dirty solution

<lang C>/*

* Write Entire File -- RossetaCode -- dirty hackish solution
*/

define _CRT_SECURE_NO_WARNINGS // turn off MS Visual Studio restrictions
include <stdio.h>

int main(void) {

   return 0 >= fputs("ANY STRING TO WRITE TO A FILE AT ONCE.", 
       freopen("sample.txt","wb",stdout));

} </lang>

Standard function fwrite()

<lang C>/*

* Write Entire File -- RossetaCode -- ASCII version with BUFFERED files
*/

define _CRT_SECURE_NO_WARNINGS

include <assert.h>
include <stdio.h>
include <stdlib.h>

/**

*  Write entire file at once.
*
*  @param fileName file name
*  @param data     buffer with data
*  @param size     number of bytes to write
*
*  @return Number of bytes have been written.
*/

int writeEntireFile(char* fileName, const void* data, size_t size) {

   size_t numberBytesWritten = 0; // will be updated

   // Notice: assertions can be turned off by #define NDEBUG
   //
   assert( fileName != NULL ); 
   assert( data != NULL );
   assert( size >  0 );

   // Check for a null pointer or an empty file name.
   //
   // BTW, should we write  if ( ptr != NULL)  or simply  if ( ptr )  ? 
   // Both of these forms are correct. At issue is which is more readable.
   //
   if ( fileName != NULL && *fileName != '\0' )
   {
       // Try to open file in BINARY MODE
       //
       FILE* file = fopen(fileName,"wb");

       // There is a possibility to allocate a big buffer to speed up i/o ops:
       //
       // const size_t BIG_BUFFER_SIZE = 0x20000; // 128KiB
       // void* bigBuffer = malloc(BIG_BUFFER_SIZE);
       // if ( bigBuffer != NULL )
       // {
       //     setvbuf(file,bigBuffer,_IOFBF,BIG_BUFFER_SIZE);
       // }
       //
       // Of course, you should release the malloc allocated buffer somewhere.
       // Otherwise, bigBuffer will be released after the end of the program.

       if ( file != NULL )
       {
           // Return value from fwrite( data, 1, size, file ) is the number
           // of bytes written. Return value from fwrite( data, size, 1, file )
           // is the number of blocks (either 0 or 1) written.
           //
           // Notice, that write (see io.h) is less capable than fwrite.
           //

           if ( data != NULL )
           {
               numberBytesWritten = fwrite( data, 1, size, file );
           }
           fclose( file );
       }
   }
   return numberBytesWritten;

}

define DATA_LENGTH 8192 /* 8KiB */

int main(void) {

   // Large arrays can exhaust memory on the stack. This is why the static 
   // keyword is used.Static variables are allocated outside the stack.
   //
   static char data[DATA_LENGTH];
   
   // Filling data array with 'A' character. 
   // Of course, you can use any other data here.
   //
   int i;
   for ( i = 0; i < DATA_LENGTH; i++ )
   {
       data[i] = 'A';
   }

   // Write entire file at once.
   //
   if ( writeEntireFile("sample.txt", data, DATA_LENGTH ) == DATA_LENGTH )
       return EXIT_SUCCESS;
   else 
       return EXIT_FAILURE;

} </lang>

POSIX function write()

<lang C>/*

* Write Entire File -- RossetaCode -- plain POSIX write() from io.h
*/

define _CRT_SECURE_NO_WARNINGS // turn off MS Visual Studio restrictions
define _CRT_NONSTDC_NO_WARNINGS // turn off MS Visual Studio restrictions

include <assert.h>
include <fcntl.h>
include <io.h>

/**

*  Write entire file at once.
*
*  @param fileName file name
*  @param data     buffer with data
*  @param size     number of bytes to write
*
*  @return Number of bytes have been written.
*/

int writeEntireFile(char* fileName, const void* data, size_t size) {

   size_t numberBytesWritten = 0; // will be updated
   int file; // file handle is an integer (see Fortran ;)

   // Notice: we can not trust in assertions to work. 
   // Assertions can be turned off by #define NDEBUG.
   //
   assert( fileName ); 
   assert( data );
   assert( size >  0 );

   if(fileName && fileName[0] && (file=open(fileName,O_CREAT|O_BINARY|O_WRONLY))!=(-1))
   {
       if ( data ) 
           numberBytesWritten = write( file, data, size );
       close( file );
   }
   return numberBytesWritten;

}

define DATA_LENGTH 8192 /* 8KiB */

int main(void) {

   // Large arrays can exhaust memory on the stack. This is why the static 
   // keyword is used.Static variables are allocated outside the stack.
   //
   static char data[DATA_LENGTH];
   
   // Filling data array with 'Z' character. 
   // Of course, you can use any other data here.
   //
   int i;
   for ( i = 0; i < DATA_LENGTH; i++ )
   {
       data[i] = 'Z';
   }

   // Write entire file at once.
   //
   if ( writeEntireFile("sample.txt", data, DATA_LENGTH ) == DATA_LENGTH )
       return 0;
   else 
       return 1;

} </lang>

C#

<lang csharp>System.IO.File.WriteAllText("filename.txt", "This file contains a string.");</lang>

C++

<lang cpp>#include <fstream> using namespace std;

int main() {

   ofstream file("new.txt");
   file << "this is a string";
   file.close();
   return 0;

}</lang>

Clojure

<lang clojure>(spit "file.txt" "this is a string")</lang>

Common Lisp

<lang lisp>(with-open-file (str "filename.txt"

                    :direction :output
                    :if-exists :supersede
                    :if-does-not-exist :create)
 (format str "File content...~%"))</lang>

D

<lang D>import std.stdio;

void main() {

   auto file = File("new.txt", "wb");
   file.writeln("Hello World!");

}</lang>

Delphi

Library: System.IoUtils

Translation of: C#

<lang Delphi> program Write_entire_file;

{$APPTYPE CONSOLE}

uses

 System.IoUtils;

begin

 TFile.WriteAllText('filename.txt', 'This file contains a string.');

end.</lang>

Elena

ELENA 4.x : <lang elena>import system'io;

public program() {

   File.assign("filename.txt").saveContent("This file contains a string.")

}</lang>

Elixir

<lang elixir>File.write("file.txt", string)</lang>

F#

<lang fsharp>System.IO.File.WriteAllText("filename.txt", "This file contains a string.")</lang>

Factor

<lang factor>USING: io.encodings.utf8 io.files ; "this is a string" "file.txt" utf8 set-file-contents</lang>

Fortran

Where F is an integer with a value such as 10 (these days not being 5, standard input, nor 6, standard output), the I/O unit number. "REPLACE" means create the file if it does not exist, otherwise delete the existing file and create a new one of that name. The WRITE statement may present a single (large?) item, a list of items, and possibly there would be a series of WRITE statements if there is no need to do the deed via one WRITE only. <lang Fortran> OPEN (F,FILE="SomeFileName.txt",STATUS="REPLACE")

     WRITE (F,*) "Whatever you like."
     WRITE (F) BIGARRAY</lang>

Earlier Fortran might have other predefined unit numbers, for a card punch, paper tape, lineprinter, and so on, according to the installation. For a disc file, there may be no facility to name the file within Fortran itself as in the example OPEN statement because there may be no OPEN statement. Fortran IV used a DEFINE FILE statement, for example, which specified the record length and number of records in the file. As constants. File naming would instead be done by commands to the operating system when the prog. is started, as with the DD statement of JCL (Job Control Language) of IBM mainframes, and this would have its own jargon for NEW, OLD, REPLACE and what to do when the step finishes: DISP=KEEP, perhaps.

The OPEN statement started becoming standard with F77, but a READ or WRITE statement for a file could mix FORMAT style I/O with unformatted I/O - or indeed do both at once. This could be achieved via the An format code, which essentially states "unformatted" because it takes the variable's bit pattern "as is". Thus, a typical 32-bit floating-point variable occupies four bytes so it could be read or written with format code A4 and so on for other sizes. With declarations like REAL*8 X, Fortran programmers are usually well aware of storage sizes.

With F90, constraints were tightened - for our own good, supposedly. A file is opened with FORM="FORMATTED" by default, meaning that text is expected to be involved and all READ or WRITE statements must use the FORMAT facilities for that file. In the example, the * specifies free-format, which is not format free. Contrariwise, if the file is opened with FORM="UNFORMATTED" then the FORMAT facility must not be specified, as in the second WRITE of the example.

There is no particular limit on how much can be written in one go since no fixed record length has been specified, and indeed the text rolled forth via a variable may contain whatever character codes are desired, including CR, LF - but you will have to know whether the record separator is CR, CRLF, LFCR or CR, if you expect the file to be read later as a series of separate records. The output from each WRITE will be followed by the record separator (whichever it is) in the character interpretation in force, usually ASCII these days.

If instead FORM="UNFORMATTED" were specified in the OPEN statement you can still write whatever you wish, but now each output will not be followed by a record terminator. It is usual for such files to have a defined record length and reading or writing more than a record can hold is deemed an error. Previously (as with Fortran IV) the output (or input) would continue into however many successive records were needed. This was convenient when writing a large array of integers or floating-point, or indeed any list of such items. This would be useful when a complex data structure had been devised, and a simple statement with a short list would write the lot to a disc file, or read it back later. This would be far less trouble than working through its many details. One could go further and use EQUIVALENCE to overlay the pieces upon a large single array (called say THELOT) so that one need merely use WRITE(F) THELOT and likewise for reading. However keeping the equivalences correct when changes are made is troublesome. Instead, the data structure's collection of items could be placed in a COMMON work area and a STASH subroutine would for its COMMON statement merely declare an array THELOT of a suitable size without any mention of EQUIVALENCE. A somewhat similar arrangement is provided in pl/i via the BASED facility.

Option FORM="BINARY" does allow the reading or writing of however many records are needed to satisfy the I/O list, but, this is not a standard usage.

Free Pascal

See also: #Pascal <lang Pascal>program overwriteFile(input, output, stdErr); {$mode objFPC} // for exception treatment uses sysUtils; // for applicationName, getTempDir, getTempFileName // also: importing sysUtils converts all run-time errors to exceptions resourcestring hooray = 'Hello world!'; var FD: text; begin // on a Debian GNU/Linux distribution, // this will write to /tmp/overwriteFile00000.tmp (or alike) assign(FD, getTempFileName(getTempDir(false), applicationName())); try rewrite(FD); // could fail, if user has no permission to write writeLn(FD, hooray); finally close(FD); end; end.</lang>

FreeBASIC

<lang freebasic>' FB 1.05.0 Win64

Open "output.txt" For Output As #1 Print #1, "This is a string" Close #1</lang>

Frink

<lang Frink> w = new Writer["test.txt"] w.print["I am the captain now."] w.close[] </lang>

Gambas

<lang gambas>Public Sub Main()

File.Save(User.home &/ "test.txt", "(Over)write a file so that it contains a string.")

End</lang>

Go

<lang Go>import "io/ioutil"

func main() {

   ioutil.WriteFile("path/to/your.file", []byte("data"), 0644)

}</lang>

Groovy

<lang Groovy> new File("myFile.txt").text = """a big string that can be splitted over lines """ </lang>

Haskell

<lang Haskell>main :: IO ( ) main = do

  putStrLn "Enter a string!"
  str <- getLine
  putStrLn "Where do you want to store this string ?"
  myFile <- getLine
  appendFile myFile str</lang>

J

<lang J> characters fwrite filename</lang>

or,

<lang J> characters 1!:2<filename</lang>

Java

<lang java>import java.io.*;

public class Test {

   public static void main(String[] args) throws IOException {
       try (BufferedWriter bw = new BufferedWriter(new FileWriter("test.txt"))) {
           bw.write("abc");
       }
   }

}</lang>

Julia

<lang julia>function writeFile(filename, data) f = open(filename, "w") write(f, data) close(f) end

writeFile("test.txt", "Hi there.")</lang>

Kotlin

<lang scala>// version 1.1.2

import java.io.File

fun main(args: Array<String>) {

   val text = "empty vessels make most noise"
   File("output.txt").writeText(text)

}</lang>

Lingo

<lang lingo>---------------------------------------- -- Saves string as file -- @param {string} tFile -- @param {string} tString -- @return {bool} success

on writeFile (tFile, tString)

 fp = xtra("fileIO").new()
 fp.openFile(tFile, 2)
 err = fp.status()
 if not (err) then fp.delete()
 else if (err and not (err = -37)) then return false
 fp.createFile(tFile)
 if fp.status() then return false
 fp.openFile(tFile, 2)
 if fp.status() then return false
 fp.writeString(tString)
 fp.closeFile()
 return true

end</lang>

LiveCode

This will create a file "TestFile.txt" or overwrite it if it already exists. This is the shortest method for file I/O in LiveCode, but not the only method. <lang LiveCode> put "this is a string" into URL "file:~/Desktop/TestFile.txt" </lang>

Lua

<lang Lua>function writeFile (filename, data) local f = io.open(filename, 'w') f:write(data) f:close() end

writeFile("stringFile.txt", "Mmm... stringy.")</lang>

Maple

<lang Maple>Export("directory/filename.txt", string);</lang>

Mathematica/Wolfram Language

<lang Mathematica>Export["filename.txt","contents string"]</lang>

Nanoquery

<lang Nanoquery>import Nanoquery.IO

new(File, fname).create().write(string)</lang>

Nim

<lang nim> writeFile("filename.txt", "An arbitrary string") </lang>

Objeck

<lang objeck>use System.IO.File;

class WriteFile {

 function : Main(args : String[]) ~ Nil {
   writer ← FileWriter→New("test.txt");
   leaving {
     writer→Close();
   };
   writer→WriteString("this is a test string");
 }

}</lang>

OCaml

<lang ocaml>let write_file filename s =

 let oc = open_out filename in
 output_string oc s;
 close_out oc;

let () =

 let filename = "test.txt" in
 let s = String.init 26 (fun i -> char_of_int (i + int_of_char 'A')) in
 write_file filename s</lang>

Pascal

See also: Free Pascal

In Standard Pascal, a list of identifiers in the program header sets up a list of file handlers. <lang Pascal>{$ifDef FPC}{$mode ISO}{$endIf} program overwriteFile(FD); begin writeLn(FD, 'Whasup?'); close(FD); end.</lang> In some environments, it is the caller’s sole responsibility to invoke the program properly. I. e., the program above could be invoked on a Bourne-again shell in this fashion: <lang bash>./overwriteFile >&- <&- 0>/tmp/foo # open file descriptor with index 0 for writing</lang>

Perl

The modern recommended way, is to use one of these CPAN modules:

<lang perl>use File::Slurper 'write_text'; write_text($filename, $data);</lang>

<lang perl>use Path::Tiny; path($filename)->spew_utf8($data);</lang>

Traditional way, in case using CPAN modules is not an option:

<lang perl>open my $fh, '>:encoding(UTF-8)', $filename or die "Could not open '$filename': $!"; print $fh $data; close $fh;</lang>

Phix

Deep in the heart of the compiler itself, after much huffing and puffing, the following code can be found: <lang Phix>fn = open(outfile,"wb") ... string img = repeat(' ',SizeOfImage) ... SetCheckSum(img,SizeOfImage) puts(fn,img) close(fn)</lang> Obviously as that can successfully write a binary executable, simple strings are no problem, except that when dealing with text you would normally want automatic line ending conversion enabled, so drop the 'b' (binary) mode option, ie the "wb" above should be just "w".

The distribution also includes the file builtins\writefile.e which declares <lang Phix>global function write_file(object file, sequence data, integer as_text = BINARY_MODE, integer encoding = ANSI, integer with_bom = 1)</lang> which is intended to be a one-line call with full unicode support, however as yet it is neither properly documented nor adequately tested.

PHP

<lang php>file_put_contents($filename, $data)</lang>

PicoLisp

<lang PicoLisp>(out "file.txt"

  (prinl "My string") )</lang>

Pike

<lang Pike>Stdio.write_file("file.txt", "My string");</lang>

PowerShell

Writes all running process details to a file in the current directory. <lang powershell> Get-Process | Out-File -FilePath .\ProcessList.txt </lang>

PureBasic

<lang PureBasic> EnableExplicit

Define fOutput$ = "output.txt" ; enter path of file to create or overwrite Define str$ = "This string is to be written to the file"

If OpenConsole()

 If CreateFile(0, fOutput$)
   WriteString(0, str$) 
   CloseFile(0)   
 Else
   PrintN("Error creating or opening output file")
 EndIf
 PrintN("Press any key to close the console")
 Repeat: Delay(10) : Until Inkey() <> ""
 CloseConsole()

EndIf </lang>

Output (contents of 'output.exe'):

This string is to be written to the file

Python

<lang python>with open(filename, 'w') as f:

   f.write(data)</lang>

Starting in Python 3.4, we can use pathlib to reduce boilerplate:

<lang python>from pathlib import Path

Path(filename).write_text(any_string) Path(filename).write_bytes(any_binary_data)</lang>

Racket

This only replaces the file if it exists, otherwise it writes a new file. Use 'truncate to overwrite the new contents into the existing file. <lang racket>#lang racket/base (with-output-to-file "/tmp/out-file.txt" #:exists 'replace

 (lambda () (display "characters")))</lang>

Raku

(formerly Perl 6)

<lang perl6>spurt 'path/to/file', $file-data;</lang> or <lang perl6>'path/to/file'.IO.spurt: $file-data;</lang>

REXX

version 1

<lang rexx> /*REXX*/

of='file.txt' 'erase' of s=copies('1234567890',10000) Call charout of,s Call lineout of Say chars(of) length(s) </lang>

Output:

100000 100000

Output:

(first time use) using Regina REXX (among others) on a Windows or DOS system

Could Not Find c:\file.txt
100000 100000

version 2

This REXX version doesn't depend on any (operating system) host commands. <lang rexx>/*REXX program writes an entire file with a single write (a long text record). */ oFID= 'OUTPUT.DAT' /*name of the output file to be used. */

                                                /* [↓]  50 bytes, including the fences.*/

$ = '<<<This is the text that is written to a file. >>>'

                                                /* [↓]  COPIES  creates a 50k byte str.*/

call charout oFID, copies($,1000), 1 /*write the longish text to the file. */

                                                /* [↑]  the "1"  writes text ──► rec #1*/
                                                /*stick a fork in it,  we're all done. */</lang>

Ring

<lang ring> write("myfile.txt","Hello, World!") </lang>

Ruby

The file is closed at the end of the block. <lang ruby>open(fname, 'w'){|f| f.write(str) }</lang>

Rust

<lang Rust>use std::fs::File; use std::io::Write;

fn main() -> std::io::Result<()> {

   let data = "Sample text.";
   let mut file = File::create("filename.txt")?;
   write!(file, "{}", data)?;
   Ok(())

}</lang>

Scala

<lang Scala>import java.io.{File, PrintWriter}

object Main extends App {

 val pw = new PrintWriter(new File("Flumberboozle.txt"),"UTF8"){
 print("My zirconconductor short-circuited and I'm having trouble fixing this issue.\nI researched" +
   " online and they said that I need to connect my flumberboozle to the XKG virtual port, but I was" +
   " wondering if I also needed a galvanized tungsten retrothruster array? Maybe it'd help the" +
   " frictional radial anti-stabilizer vectronize from the flumberboozle to the XKG virtual port?")
 close()}

}</lang>

SenseTalk

<lang sensetalk>put "New String" into file "~/Desktop/myFile.txt"</lang>

Sidef

With error handling: <lang ruby>var file = File(__FILE__) file.open_w(\var fh, \var err) || die "Can't open #{file}: #{err}" fh.print("Hello world!") || die "Can't write to #{file}: #{$!}"</lang> Without error handling: <lang ruby>File(__FILE__).open_w.print("Hello world!")</lang>

Smalltalk

Works with: Smalltalk/X

<lang smalltalk>'file.txt' asFilename contents:'Hello World'</lang>

SPL

<lang spl>#.writetext("file.txt","This is the string")</lang>

Standard ML

<lang sml>fun writeFile (path, str) =

 (fn strm =>
   TextIO.output (strm, str) before TextIO.closeOut strm) (TextIO.openOut path)</lang>

Tcl

<lang Tcl>proc writefile {filename data} {

   set fd [open $filename w]   ;# truncate if exists, else create
   try {
       puts -nonewline $fd $data
   } finally {
       close $fd
   }

}</lang>

A more elaborate version of this procedure might take optional arguments to pass to fconfigure (such as encoding) or open (such as permissions).

TUSCRIPT

<lang tuscript> $$ MODE TUSCRIPT content="new text that will overwrite content of myfile" LOOP

path2file=FULLNAME (TUSTEP,"myfile",-std-)
status=WRITE (path2file,content)
IF (status=="OK") EXIT
IF (status=="CREATE") ERROR/STOP CREATE ("myfile",seq-o,-std-)

ENDLOOP </lang>

VBA

<lang vb> Option Explicit

Const strName As String = "MyFileText.txt" Const Text As String = "(Over)write a file so that it contains a string. " & vbCrLf & _

          "The reverse of Read entire file—for when you want to update or " & vbCrLf & _
          "create a file which you would read in its entirety all at once."

Sub Main() Dim Nb As Integer

Nb = FreeFile Open "C:\Users\" & Environ("username") & "\Desktop\" & strName For Output As #Nb

   Print #1, Text

Close #Nb End Sub</lang>

VBScript

Text file created or overwritten in the same folder as the script. <lang vb> Set objFSO = CreateObject("Scripting.FileSystemObject")

SourceFile = objFSO.GetParentFolderName(WScript.ScriptFullName) & "\out.txt" Content = "(Over)write a file so that it contains a string." & vbCrLf &_ "The reverse of Read entire file—for when you want to update or create a file which you would read in its entirety all at once."

With objFSO.OpenTextFile(SourceFile,2,True,0) .Write Content .Close End With

Set objFSO = Nothing </lang>

Visual Basic .NET

Translation of: C#

<lang vbnet>Module Module1

   Sub Main()
       My.Computer.FileSystem.WriteAllText("new.txt", "This is a string", False)
   End Sub

End Module </lang>

Wren

The easiest way to overwrite a file in Wren is to 'create' it again which truncates the existing contents. <lang ecmascript>import "io" for File

// create a text file File.create("hello.txt") { |file|

   file.writeBytes("hello")

}

// check it worked System.print(File.read("hello.txt"))

// overwrite it by 'creating' the file again File.create("hello.txt") {|file|

   file.writeBytes("goodbye")

}

// check it worked System.print(File.read("hello.txt"))</lang>

Output:

hello
goodbye

XLISP

<lang scheme>(define n (open-output-file "example.txt")) (write "(Over)write a file so that it contains a string." n) (close-output-port n)</lang>

XPL0

<lang XPL0>[FSet(FOpen("output.txt", 1), ^o); Text(3, "This is a string."); ]</lang>

Xtend

<lang java> package com.rosetta.example

import java.io.File import java.io.PrintStream

class WriteFile {

   def static main( String ... args ) {
       val fout = new PrintStream(new File(args.get(0)))
       fout.println("Some text.")
       fout.close
   }

} </lang>

Yabasic

<lang Yabasic>open "output.txt" for writing as #1 print #1 "This is a string" close #1</lang>

zkl

<lang zkl> // write returns bytes written, GC will close the file (eventually) File("foo","wb").write("this is a test",1,2,3); //-->17

f:=File("bar",wb"); data.pump(f,g); // use g to process data as it is written to file f.close(); // don't wait for GC</lang>

@@ Line 592: / Line 592: @@
 <lang Maple>Export("directory/filename.txt", string);</lang>
-=={{header|Mathematica}}==
+=={{header|Mathematica}}/{{header|Wolfram Language}}==
 <lang Mathematica>Export["filename.txt","contents string"]</lang>