Javascript write to file

Are you looking for the ways to access the file system using JavaScript? If your JavaScript code could access local files of the visitor to your site, it would be a huge security problem. That's why no browsers would allow it...

JavaScript is a simple yet very powerful scripting language. Why not use your knowledge of JavaScript for batch processing of local files and other common tasks?
Well, you can! Not through the Internet of course, but internally on your computer, or on your intranet if you have one.

How can you use JavaScript to access your local files and folders? Currently there are two ways to do it:

1. Using JavaScript extensions (runs from JavaScript Editor), or
2. Using a web page and ActiveX objects (Internet Explorer only)

Using ActiveX objects gives you many possibilities, but there are two distinct disadvantages:

You need a web page to run your JavaScript, and
ActiveX objects only work with the Internet Explorer browser.

When using extensions, all you need to do is select Build / Execute from the menu and let JavaScript Editor do the job.

Example 1 (using extensions): Reading a file

1. Run JavaScript Editor
2. Copy and paste the code below
3. Save the file as FileRead.js, and
4. Select Build / Execute from the menu.

Note: If you do not save the file, getScriptPath() below will return an empty string.

// This example shows file manipulation routines: it echoes
// the contents of itself (the script file).
// Created with Antechinus® JavaScript Editor
// Copyright© 2000-2005 C Point Pty Ltd

fh = fopen(getScriptPath(), 0 ); // Open the file for reading
if (fh!=- 1 ) // If the file has been successfully opened
{
    length = flength(fh);         // Get the length of the file    
    str = fread(fh, length);     // Read in the entire file
    fclose(fh);                     // Close the file
    
// Display the contents of the file    
    write(str);    
}

Example 2 (using extensions): Listing files in a folder

1. Run JavaScript Editor
2. Copy and paste the code below
3. Save the file as FolderExample.js, and
4. Select Build / Execute from the menu.

Note: if you do not save the file, getCurrentFolder() below will return an empty string.

// This example shows folder manipulation routines: it lists
// the contents of the current folder.
// Created with Antechinus® JavaScript Editor
// Copyright© 2000-2006 C Point Pty Ltd

write( "The contents of " + getCurrentFolder());

fileName = findFirstFile( "*.*" ); // Find the first file matching the filter
while (fileName.length)
{
    write(fileName);
    fileName = findNextFile();  // Find the next file matching the filter
}

Example 2 (using ActiveX and a web page): Listing available drives

1. Run JavaScript Editor
2. Copy and paste the code below
3. Save the file as DriveList.htm, and
4. View the page using Internal Viewer or Internet Explorer

< HTML >
< HEAD >

< SCRIPT language = JavaScript>

function ShowAvailableDrives()
{
    document.write(GetDriveList());
}

function GetDriveList()
{
&nbspvar fso,  s,  n,  e,  x;
 fso  = new ActiveXObject( "Scripting.FileSystemObject" );
 e  = new Enumerator(fso.Drives);
 s  =  "" ;
&nbspdo
 {
   x  =  e.item();
   s  =  s  +  x.DriveLetter;
   s  +=  ":-    " ;
  &nbspif (x.DriveType  ==  3 )     n  =  x.ShareName;
  &nbspelse if (x.IsReady)     n  =  x.VolumeName;
  &nbspelse                     n  =  "[Drive not ready]" ;
   s  +=  n  +  "<br>" ;
   e.moveNext();
 } &nbspwhile (!e.atEnd());
 
&nbspreturn (s);
}

</ SCRIPT >
</ HEAD >

< BODY >
< P>
< SCRIPT language=JavaScript>  ShowAvailableDrives(); </ SCRIPT>
</ P>
</ BODY>
</ HTML >

Putting it all together:

Use JavaScript for batch processing and other common tasks of your local and intranet files
Using ActiveX objects works well, but you need a web page to run your JavaScript
ActiveX objects work on Internet Explorer, but not on Opera, Netscape or Firefox
When using JavaScript extensions you do not need a web page: run your code straight from the JavaScript Editor.