Active Server Pages Tutorial

Accessing the File System

The FileSystemObject Object

The FileSystemObject object lets you create and work with files and directories on the server. For example, you can create a file, write data to it and then delete it when the file is no longer necessary. You can also determine whether or not certain files exist, as well as their locations, extensions and other information.

FileSystemObject Object: Methods
BuildPath	Adds a folder or file name to a path.
CopyFile	Copies a file from one location to another.
CopyFolder	Copies a folder and all its files from one location to another.
CreateFolder	Creates a new folder.
CreateTextFile	Creates a new text file using the TextStream object.
DeleteFile	Deletes a file.
DeleteFolder	Deletes a folder and all its files.
DriveExists	Determines whether or not a drive exists on the server.
FileExists	Determines whether or not a file exists on the server.
FolderExists	Determines whether or not a folder exists on the server.
GetAbsolutePathName	Returns the full path (from the root) for the specified folder or file.
GetBaseName	Returns the base name (without the extension) of the specified file or folder.
GetDrive	Creates an instance of the Drive object.
GetDriveName	Returns the drive containing the specified file.
GetExtensionName	Returns the extension of the specified file.
GetFile	Creates an instance of the File object.
GetFileName	Returns the file or folder name specified in a path.
GetFolder	Creates an instance of the Folder object.
GetParentFolderName	Returns the name of the parent folder for the specified file.
GetSpecialFolder	Returns the path of a special Windows folder. 0 returns the path for the folder containing the operating system; 1 returns the path for the folder containing libraries and drivers; 2 returns the path for the Temp folder.
GetTempName	Generates a temporary file or folder with a random name.
MoveFile	Moves a file from one location to another on the server.
MoveFolder	Moves a folder and all its files from one location to another on the server.
OpenTextFile	Opens a file using the TextStream object.

FileSystemObject Object: Properties
Drives	Returns a collection of Drive objects.

The following code determines whether or not a certain file (temp.txt) exists on the server and, if it does, deletes it:

<% Dim varFileSystem Set varFileSystem=Server.CreateObject(“Scripting.FileSystemObject”) If varFileSystem.FileExists(“c:\inetpub\wwwroot\temp.txt”)=true then varFileSystem.DeleteFile(“c:\inetpub\wwwroot\temp.txt”) End If %>

Once you’ve created a FileSystemObject object, you can use its methods to create instances of the TextStream object, the File object, the Folder object and the Drive object. All of these have methods and properties of their own that let you create and manipulate specific files, folders and drives on the server.

The TextStream Object

The TextStream object lets you create and work with a text file.

TextStream Object: Methods
Close	Closes the text file.
Read	Returns a specified number of characters from a text file.
ReadAll	Returns an entire text file.
ReadLine	Returns a line from a text file.
Skip	Skips a specified number of characters when reading a text file.
SkipLine	Skips a line when reading a text file.
Write	Writes text to a text file.
WriteLine	Writes a line of text to a text file.
WriteBlankLine	Writes the specified number of blank lines to a text file.

TextStream Object: Properties
AtEndOfLine	Is “true” if the location is just before the end of a line in a text file.
AtEndOfStream	Is “true” if the location is at the end of a text file.
Column	Returns the column number of the current character.
Line	Returns the line number of the current position.

The following code creates a text file, writes a line that contains title text, creates two blank lines, writes heading text using tabs (the ASCII code chr(9)) between the headings, and then creates another blank line before closing the file:

<% Dim varFileSystem, varTextStream Set varFileSystem=Server.CreateObject(“Scripting.FileSystemObject”) Set varTextStream=varFileSystem.CreateTextFile(“c:\plist.txt”) varTextStream.WriteLine “Company Call List” varTextStream.WriteBlankLines(2) varTextStream.Write “Name” & chr(9) varTextStream.Write “Employee ID” & chr(9) varTextStream.Write “Phone Number” varTextStream.WriteBlankLines(1) varTextStream.Close %>

You must close the file in order to allow users to access it. Once you’ve created a text file, you can use the TextStream object to open the file and display its contents in an ASP page:

<% Dim varFileSystem, varTextStream Set varFileSystem=Server.CreateObject(“Scripting.FileSystemObject”) Set varTextStream=varFileSystem.OpenTextFile(“c:\plist.txt”) Response.Write(varTextStream.ReadAll) %>

The File Object

You use the File object to return information about files on the server, and to copy, move and delete files as necessary.

File Object: Methods
Copy	Copies a file from one location to another.
Delete	Deletes a file.
Move	Moves a file from one location to another.
OpenAsTextStream	Opens the file using an instance of the TextStream object.

File Object: Properties
Attributes	Specifies or returns attributes of the specified file.
DateCreated	Returns the date and time a file was created.
DateLastAccessed	Returns the date and time a file was last accessed.
DateLastModified	Returns the date and time a file was last modified.
Drive	Returns the letter of the drive where a specified file resides.
Name	Specifies or returns the name of a file.
ParentFolder	Returns the parent object for a file using an instance of the Folder object.
Path	Returns the path for a file.
ShortName	Returns the short name of a file.
ShortPath	Returns the short path of a file.
Size	Returns the size of a file.
Type	Returns the type of a file.

The following code copies a file to an archives folder and then deletes the original file:

<% Dim varFileSystem,varFile Set varFileSystem=Server.CreateObject(“Scripting.FileSystemObject”) Set varFile=varFileSystem.GetFile(“c:\plist.txt”) varFile.Copy(“c:\archives\plist.text”) varFile.Delete Set varFile=nothing Set varFileSystem=nothing %>

The Folder Object

You use the Folder object to return information about folders on the server, and to copy, move and delete folders as necessary.

Folder Object: Methods
Copy	Copies a folder from one location to another.
Delete	Deletes a folder.
Move	Moves a folder from one location to another.
CreateTextFile	Creates a text file in the specified folder using an instance of the TextStream object.

Folder Object: Properties
Attributes	Specifies or returns attributes of the specified folder.
DateCreated	Returns the date and time a folder was created.
DateLastAccessed	Returns the date and time a folder was last accessed.
DateLastModified	Returns the date and time a folder was last modified.
Drive	Returns the letter of the drive where a specified folder resides.
IsRootFolder	Is “true” if the folder is a root folder.
Name	Specifies or returns the name of a folder.
ParentFolder	Returns the parent folder.
Path	Returns the path for a folder.
ShortName	Returns the short name of a folder.
ShortPath	Returns the short path of a folder.
Size	Returns the size of a folder.
Type	Returns the type of a folder.

The following code displays the date the archives folder was last accessed:

<% Dim varFileSystem,varFolder Set varFileSystem=Server.CreateObject(“Scripting.FileSystemObject”) Set varFolder=varFileSystem.GetFolder(“c:\archives”) Response.Write(varFolder.DateLastAccessed) Set varFolder=nothing Set varFileSystem=nothing %>

The Drive Object

You use the Drive object to return information about a local or network drive.

Drive Object: Properties
AvailableSpace	Returns the amount of available space on the specified drive.
DriveLetter	Returns the drive letter of the specified drive.
DriveType	Returns the type of the specified drive.
FileSystem	Returns the file system in use on the drive.
FreeSpace	Returns the amount of free space on the specified drive.
IsReady	Is “true” if the specified drive is ready.
Path	Returns the path for the specified drive.
RootFolder	Returns the root folder of the specified drive using an instance of the Folder object.
SerialNumber	Returns the serial number of the specified drive.
ShareName	Returns the network share name of the specified drive.
TotalSize	Returns the total size of the specified drive.
VolumeName	Specifies or returns the volume name of the drive.

The following code displays a drive’s available space:

<% Dim varFileSystem,varDrive Set varFileSystem=Server.CreateObject(“Scripting.FileSystemObject”) Set varDrive=varFileSystem.GetDrive(“c:”) Response.Write(“Available space on Drive ” & varDrive & “:”) Response.Write(varDrive.AvailableSpace) set varDrive=nothing set varFileSystem=nothing %>