Reading Files in ASP and How to Search for a particular text in all files in a specific directory.

• Download source files - 1.42 Kb

Introduction

FileSystemObject provides access to a computer's file system. Some of the common tasks that can be performed using FileSystemObject are to check for a particular folder, drive, or file, and create/modify/delete files (if you have proper folder/file permissions).

Let's Start

To start with, following is the code which describes how to use the FileSystemObject to create a text file, and write some text:

    Set fso = CreateObject("Scripting.FileSystemObject")
    Set a = fso.CreateTextFile("c:\testfile.txt", True)
    a.WriteLine("This is a test.")
    a.Close
    set a = nothing
    set fso = nothing 

You create an instance of FileSystemObject, and create a text file c:\testfile.txt, and write some text into it. The second method to create a text file is by using OpenTextFile method of FileSystemObject object with ForWriting flag.

    Const ForWriting = 2
    Set a = fsoOpenTextFile ("c:\testfile.txt", ForWriting ,True)

You can use WriteLine or Write method to write the contents. The basic difference between WriteLine and Write is, Write writes with a trailing newline character, and WriteLine without a trailing newline character. You can use WriteBlankLines method to write blank lines.

For example, to write three blank lines, you could use the following:

    a.WriteBlankLines(3)

Following are the modes, by which files can be opened:

• ForReading (Constant value - 1) - Open a file for reading only.
• ForWriting (Constant value - 2) - Open a file for writing.
• ForAppending (Constant value - 8) - Open a file and write to the end of the file.

For example, to declare constant for reading:

    Const ForReading = 1

Let's see an example to read a text file:

    dim s
    Const ForReading = 1
    Set fso = CreateObject("Scripting.FileSystemObject")
    Set a = fso.OpenTextFile("c:\testfile.txt", ForReading)
    s = ts.ReadLine
    a.Close
    set a = nothing
    set fso = nothing 
    Response.Write "File Content : '" & s & "'"

For reading contents from the file, following methods will be used:

To read a specified number of characters from a file, use Read method. To read an entire line (all except the newline character), use ReadLine method. To read the entire contents of a text file, use ReadAll method.

Let's have a quick look at how to move, copy and delete files:

1. To move a file, use File.Move or FileSystemObject.MoveFile.
2. To copy a file, use File.Copy or FileSystemObject.CopyFile.
3. To delete a file, use File.Delete or FileSystemObject.DeleteFile.

Following example will show as to how to manipulate a file using File methods:

   Dim fso
   
   Set fso = CreateObject("Scripting.FileSystemObject")
      
   'Move a File

   Set f2 = fso.GetFile("c:\testfile.txt")
   f2.Move ("c:\temp\testfile.txt")    ' Move the file to \temp directory.

   
   'Copy file to \temp.

   f2.Copy ("c:\temp\testfile.txt")
   
   'Delete File 

   Set f2 = fso.GetFile("c:\tmp\testfile.txt")
   f2.Delete

Following example will show as to how to manipulate a file using FileSystemObject methods:

   Dim fso
   Set fso = CreateObject("Scripting.FileSystemObject")
      
   'Move a File

   Set f2 = fso.GetFile("c:\testfile.txt")
   fso.MoveFile("source_file", "destination");
   
   'Copy file to c:\temp folder

   fso.CopyFile "c:\testfile.txt", "c:\temp\"
   
   'Delete File 

   fso.DeleteFile "c:\testfile.txt"

Sample: How to search for a particular string in a specific folder in all files

Form to accept the string will be as follows:

    <FORM METHOD=POST id=form1 action="searchresult.asp" 
                           name=form1 onsubmit="return Check();">
      Enter text to search for:
      <INPUT TYPE=TEXT NAME=TextToSearch>
      <P>
      <INPUT TYPE=SUBMIT VALUE="Begin Search!" id=SUBMIT1 name=SUBMIT1>
    </FORM>

To search for a string in particular folder, following is the code: (searchresults.asp)

    'Search Text

    Dim strtextToSearch
    strtextToSearch = Request("TextToSearch")

    'Now, we want to search all of the files

    Dim fso

    'Constant to read

    Const ForReading = 1
    Set fso = Server.CreateObject("Scripting.FileSystemObject")

    'Specify the folder path to search.

    Dim FolderToSearch
    FolderToSearch = "D:\temp"
    
    'Proceed if folder exists

    if fso.FolderExists(FolderToSearch) then 
        
        Dim objFolder    
        Set objFolder = fso.GetFolder(FolderToSearch)
        
        Dim objFile, objTextStream, strFileContents, bolFileFound
        bolFileFound = False

        Dim FilesCounter
        FilesCounter = 0 'Total files found


        For Each objFile in objFolder.Files
            Set objTextStream = fso.OpenTextFile(objFile.Path,ForReading)
            'Read the content

            strFileContents = objTextStream.ReadAll
            If InStr(1,strFileContents,strtextToSearch,1) then
               Response.Write objFile.Name & "<br>"
               FilesCounter = FilesCounter + 1
            End If
            objTextStream.Close
        Next

        if FilesCounter = 0 then 
            Response.Write "Sorry, No matches found."
        else
            Response.Write "Total files found : " & FilesCounter
        end if    
        
        'Destroy the objects

        Set objTextStream = Nothing
        Set objFolder = Nothing

    else
        Response.Write "Sorry, invalid folder name"
    end if
    Set fso = Nothing

Summary

This article gives you a brief introduction about FileSystemObject, how to create/delete text files, and an example of how to use FileSystemObject to search for a particular string in all files located in a specific folder.

References

• MSDN.