Scripting the File System, Part I: GetTempName() through OpenTextFile() - Doc JavaScript | WebReference

Scripting the File System, Part I: GetTempName() through OpenTextFile() - Doc JavaScript


Scripting the File System, Part I

GetTempName() through OpenTextFile()

GetTempName()String

This method returns a randomly-generated temporary file or folder. On a Windows installation, this file may start with "rad", followed by a random sequence of five alphanumeric characters. Use this method in applications where you need to create temporary files with unique names. The following script should pop up an alert box with a string that looks like "radEF98E.tmp":

<SCRIPT LANGUAGE="JavaScript">
<!--
var fso = new ActiveXObject("Scripting.FileSystemObject");
tmpName = fso.GetTempName();
alert(tmpName);
-->
</SCRIPT>
MoveFile(source, destination)Undefined

This method moves a source file to a destination file. If the destination file exists, the file will not be moved and you'll get the "File already exists" error message. Here is a script that moves test.txt from d:\ to d:\yehuda:

<SCRIPT LANGUAGE="JavaScript">
<!--
var fso = new ActiveXObject("Scripting.FileSystemObject");
var newpath = fso.CopyFile("d:\\test.txt", "d:\\yehuda\\test.txt");
-->
</SCRIPT>
MoveFolder(source, destination)Undefined

This method moves a source folder to a destination folder. If the destination folder exists, the folder will not be moved and you'll get the "File already exists" error message. Here is a script that moves new from d:\ to d:\yehuda:

<SCRIPT LANGUAGE="JavaScript">
<!--
var fso = new ActiveXObject("Scripting.FileSystemObject");
var newpath = fso.CopyFile("d:\\new", "d:\\yehuda\\new");
-->
</SCRIPT>
OpenTextFile(fileName, iomode, create, format)Object

This method opens a text stream object to the specified file, fileName, for reading and writing. The second parameter, iomode, indicates the mode of the file opening. Possible values are:

ConstantValueDescription
ForReading1Opens the file for reading
ForWriting2Opens the file for writing
ForAppending8Opens the file for appending

You need to set the constants yourself. JavaScript does not support them by itself. The third parameter, create, is a Boolean value indicating whether to create the file if does not exist (true) or to issue an error message if the file does not exist (false). The last parameter, format, is optional and indicates the file type. If not specified, the default file type is ASCII. The possible values of format are:

ConstantValueDescription
TristateUseDefault-2Opens the file using the system default
TristateTrue-1Opens the file as Unicode
TristateFalse0Opens the file as ASCII

You need to set these constants yourself. JavaScript does not set them by itself. Here is a script that opens the file f:\yehuda\js\tips\001122.html for writing as an ASCII. It creates the file if it does not already exist:

<SCRIPT LANGUAGE="JavaScript">
<!--
var ForWriting = 2;
var TriStateFalse = 0;
var fso = new ActiveXObject("Scripting.FileSystemObject");
var newFile = fso.OpenTextFile("f:\\yehuda\\js\\tips\\001122.html",
  ForWriting, true, TriStateFalse);
-->
</SCRIPT>

Next: How to use GetFile()

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Produced by Yehuda Shiran and Tomer Shiran
All Rights Reserved. Legal Notices.
Created: November 20, 2000
Revised: November 20, 2000

URL: http://www.webreference.com/js/column71/***PASTE FILENAME HERE***