One of the most important tasks in any programming language is the ability to read and write files. The steps involved in ASP are no different than many other languages:
- Specify the location of the file
- Determine if the file exists
- Get a handle to the file
- Read the contents
- Close the file and release any resources used
File I/O in ASP can be done using the FileSystemObject
component. When opening a text file you simply open it as a text stream, and it is this text stream that you use to access the contents of the file.
The FileSystemObject allows you to perform all file and folder handling operations. It can either return a file which can then be opened as a text stream, or it can return a text stream object directly.
In the following I present two different methods. The first method gets a file object and uses that to open the text stream, and the second method opens the text stream directly from the FileSystemObject
.
Method 1:
<% Option Explicit
Const Filename = "/readme.txt"
Const ForReading = 1, ForWriting = 2, ForAppending = 3
Const TristateUseDefault = -2, TristateTrue = -1, TristateFalse = 0
Dim FSO
set FSO = server.createObject("Scripting.FileSystemObject")
Dim Filepath
Filepath = Server.MapPath(Filename)
if FSO.FileExists(Filepath) Then
Dim file
set file = FSO.GetFile(Filepath)
Dim FileSize
FileSize = file.Size
Response.Write "<p><b>File: " & Filename & " (size " & FileSize &_
" bytes)</b></p><hr>"
Response.Write "<pre>"
Dim TextStream
Set TextStream = file.OpenAsTextStream(ForReading, TristateUseDefault)
Do While Not TextStream.AtEndOfStream
Dim Line
Line = TextStream.readline
Line = Line & vbCRLF
Response.write Line
Loop
Response.Write "</pre><hr>"
Set TextStream = nothing
Else
Response.Write "<h3><i><font color=red> File " & Filename &_
" does not exist</font></i></h3>"
End If
Set FSO = nothing
%>
Method 2:
<% Option Explicit
Const Filename = "/readme.txt"
Const ForReading = 1, ForWriting = 2, ForAppending = 3
Const TristateUseDefault = -2, TristateTrue = -1, TristateFalse = 0
Dim FSO
set FSO = server.createObject("Scripting.FileSystemObject")
Dim Filepath
Filepath = Server.MapPath(Filename)
if FSO.FileExists(Filepath) Then
Set TextStream = FSO.OpenTextFile(Filepath, ForReading, False, TristateUseDefault)
Dim Contents
Contents = TextStream.ReadAll
Response.write "<pre>" & Contents & "</pre><hr>"
TextStream.Close
Set TextStream = nothing
Else
Response.Write "<h3><i><font color=red> File " & Filename &_
" does not exist</font></i></h3>"
End If
Set FSO = nothing
%>
Chris Maunder is the co-founder of
CodeProject, DeveloperMedia and ContentLab, and has been a prominent figure in the software development community for nearly 30 years. Hailing from Australia, Chris has a background in Mathematics, Astrophysics, Environmental Engineering and Defence Research. His programming endeavours span everything from FORTRAN on Super Computers, C++/MFC on Windows, through to to high-load .NET web applications and Python AI applications on everything from macOS to a Raspberry Pi. Chris is a full-stack developer who is as comfortable with SQL as he is with CSS.
In the late 1990s, he and his business partner David Cunningham recognized the need for a platform that would facilitate knowledge-sharing among developers, leading to the establishment of CodeProject.com in 1999. Chris's expertise in programming and his passion for fostering a collaborative environment have played a pivotal role in the success of CodeProject.com. Over the years, the website has grown into a vibrant community where programmers worldwide can connect, exchange ideas, and find solutions to coding challenges. Chris is a prolific contributor to the developer community through his articles and tutorials, and his latest passion project,
CodeProject.AI.
In addition to his work with CodeProject.com, Chris co-founded ContentLab and DeveloperMedia, two projects focussed on helping companies make their Software Projects a success. While at CodeProject, Chris' roles included Architecture and coding, Product Development, Content Creation, Community Growth, Client Satisfaction and Systems Automation, and many, many sales meetings. All while keeping his sense of humour.