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This section covers how to work with files--how to COPY, move, and delete files; how to detect whether a file exists; and how to retrieve the attributes of a file.

Copying, Moving, and Deleting Files

There's more than one way to copy, move, or delete a file.  To do this, you can use the methods of the FileSystemObject object or the methods of the File object.  The methods of the FileSystemObject object are slightly more flexible because you're not restricted to working with a single file.

The following list describes the methods of the FileSystemObject for manipulating files:

  • CopyFile source, destination, [overwrite].  This method copies a file from one location to another.  You can use wildcards in the source parameter to copy more than one file at a time.  The optional overwrite parameter indicates whether to overwrite an existing file.  It can have the value TRUE or the value FALSE.
  • MoveFile source, destination.  This method moves a file from one location to another.  You can use wildcards in the source parameter to move more than one file at a time.  If the file already exists at the destination, an error is generated.
  • DeleteFile FileSpecifier.  This method deletes the specified file.  You can use wildcards to delete more than one file at a time.  If you use wildcards and no matches are made, an error is generated.

Before you can use any of these methods, however, you first need to create an instance of the FileSystemObject object.  The next example shows how each of the methods is Used:

<%
'   Create an instance of the FileSystemObject object
Set MyFileObject=Server.CreateObject("Scripting.FileSystemObject")
'   Create a file to manipulate
Set MyFile=MyFileObject.CreateTextFile("c:\test.txt")
MyFile.Writeline("Hello")
MyFile.Close
'   Copy the file
MyFileObject.CopyFile "c:\test.txt","c:\test2.txt"
'   Move the file
MyFileObject.MoveFile "c:\test2.txt","c:\test3.txt"
'   Delete both files
MyFileObject.DeleteFile "c:\test.txt"
MyFileObject.DeleteFile "c:\test3.txt"
%>

Instead of using the FileSystemObject object to copy, move, or delete files, you can also use the File object.  These are the equivalent methods you can use with the File object:

  • Copy newcopy, [Overwrite].  This method creates a new copy of the current file.  If the optional overwrite parameter is set to TRUE, any preexisting file is overwritten.
  • Move newcopy.  This method moves the current file.  The current file will now refer to this file.
  • Delete.  Deletes the current file.

Before you can use these methods, you must first create an instance of the File object.  To create an instance of the File object, you can use the GetFile( ) method of the FileSystemObject object.  Here's the preceding script, rewritten to use the methods of the File object:

<%
'   Create an instance of the FileSystemObject object
Set MyFileObject=Server.CreateObject("Scripting.FileSystemObject")
'   Create a file to manipulate
Set MyFile=MyFileObject.CreateTextFile("c:\test.txt")
MyFile.Writeline("Hello")
MyFile.Close
'   Create an instance of the File object.
Set afile=MyFileObject.GetFile("c:\test.txt")
'   Copy the file
afile.Copy "c:\test2.txt"
'   Move the file
afile.Move "c:\test3.txt"
'   Delete the original file
afile.Delete
%>

Detecting Whether a File Exists

To detect whether or not a particular file exists, you can use the FileExists( ) method of the FileSystemObject object.  Simply pass the physical path of a file to this method and it will return either TRUE or FALSE.  Here's an example of how this method is used:

<HTML>
<HEAD><TITLE> FileExists Example </TITLE></HEAD>
<BODY>
<%
MySelf=Request.ServerVariables("PATH_TRANSLATED")
'   Create an instance of the FileSystemObject object
Set MyFileObject=Server.CreateObject("Scripting.FileSystemObject")
If MyFileObject.FileExists(Myself) THEN
Response.Write("l exist!")
ELSE
Response.Write("I do not exist.")
END IF
%>
</BODY>
</HTML>

This Active Server Page checks whether or not it exists.  The server variable PATH_TRANSLATED is used to return the physical path of the current file.  The FileExists method checks whether this file exists.  In this example, necessarily, the method must always return TRUE. (In other words, A checks to see whether A itself exists, and of course it does, so it comes back TRUE.)

Retrieving the Attributes of Files

The File object includes a number of properties that are useful when working with files.  The following list explains these properties:

  • Attributes.  This property returns the attributes of the current file (like the DOS ATTRIB command).  For example, you can use this property to determine whether a file is hidden or read-only.
  • Datecreated.  This property returns the date and time the file was created.
  • DateLastAccessed.  This property returns the date and time the file was last accessed.
  • DateLastModified.  This property returns the date and time the file was last modified.
  • Drive.  This property returns the drive where the file is located.
  • Name.  This property returns the name of the file.
  • ParentFolder.  This property returns the folder in which the file is contained.
  • Path.  This property returns the path of the file.
  • Size.  This property returns the size of the file in bytes.
  • Type.  This property returns the type of the file--for example, Text Document, ASP File, or Internet Document (HTML).

To use any of these properties, you must first create an instance of the File object.  The next example displays all the properties for a file with the path c:\test.txt:

<HTML>
<HEAD><TITLE>File Properties</TITLE></HEAD>
<BODY>
<%
'   Create an instance of the FileSystemObject object
Set MyFileObject=Server.CreateObject("Scripting.FileSystemObject")
'   Create an instance of the File object.
Set afile=MyFileObject.GetFile("C:\test.txt")
%>
<BR>Name:   <%=afile.Name%>
<BR>Path:     <%=afile.Path%>
<BR>Drive:     <%=afile.Drive%>
<BR>Size:     <%=afile.Size%>
<BR>Type:     <%=afile.Type%>
<BR>Attributes:   <%=afile.Attributes%>
<BR>Date Created: <%=afile.DateCreated %>
<BR>Date Last Accessed: <%=afile.DateLastAocessed%>
<BR>Date Last Modified: <%=afile.DateLastModified%>
</BODY>
</HTML>

The Attributes property requires some explanation.  This property returns a number corresponding to the sum of the file attributes that have been set.  The following table lists the file attribute values.

          Attribute                                Value

         Normal                                    0

          Read-only                                1

          Hidden                                    2

          System                                   4

          Volume                                   8

          Directory                                16

          Archive                                   32

          Alim                                       64

          Compressed                          128

The file has its hidden and archive attributes set.  The combination of the Values 2 (for hidden) and 32 (for archive) equals 34.  There's no danger of ambiguity, because every combination of attribute values yields a unique number.

Some of these properties not only can be read, but also can be set.  You can set the read-only, hidden, system, and archive properties.  For example, to make the file c:\test.txt hidden, you could use the following script:

<%
'   Create an instance of the FileSystemObject object
Set MyFileObject=Server.CreateObject("Scripting.FileSystemObject")
'   Create an instance of the File object.
Set afile=MyFileObject.GetFile("c:\test.txt")
'   Make it hidden
afile.attributes=2
%>