Perform In-Place file edit with VBScript
Recently had the need to search and replace a configuration file on a system. This was part of an installation of an older program that required a variable to be replace with the computername. Being that the systems were Windows of several different releases (2000, 2003 and 2008) I could not use Powershell to complete the task and went with vbscript as the tool of choice.
Here is what the script looks like. In this example I am editing the config.ini file and looking for WIN01 and replacing it with the computername.
Const ForReading = 1
Const ForWriting = 2
Const FileIn = "c:\oldasdirt\bin\config.ini"
Const FileOut = "c:\oldasdirt\bin\config.ini"
Set objFSO = CreateObject("Scripting.FileSystemObject")
Set objFile = objFSO.OpenTextFile(FileIn, ForReading)
Set wshShell = WScript.CreateObject( "WScript.Shell" )
strComputer =wshShell.ExpandEnvironmentStrings( "%COMPUTERNAME%" )
strText = objFile.ReadAll
objFile.Close
strNewText = Replace(strText, "WIN01", strComputer)
Set objFile = objFSO.OpenTextFile(FileOut, ForWriting)
objFile.WriteLine strNewText
objFile.Close
The script can be broken done into several sections.
- define constants
- set objects
- set variables
- do the work
- close it up
For define constants we need to define the file for Reading and Writing and also define the input and output file.
Const ForReading = 1 Const ForWriting = 2 Const FileIn = "path to input file" Const FileOut = "path to output file"
There are three File input / output constants available as shown in the table below.
| Constant | Value | Description |
| ForReading | 1 | Open a file for reading only. No writing to this file can take place. |
| ForWriting | 2 | Open a file for writing. If a file with the same name exists, its previous contents are overwritten. |
| ForAppending | 8 | Open a file and write to the end of the file. |
For FileIn and FileOut we just need to put the location and name of the file we want to edit.
Next we need to set the file system object , set the File object and set the shell environment.
Set objFSO = CreateObject("Scripting.FileSystemObject")
Set objFile = objFSO.OpenTextFile(FileIn, ForReading)
Set wshShell = WScript.CreateObject( "WScript.Shell" )
Now we want to create a variable called strComputer and get the Environment variable for %COMPUTERNAME%.
strComputer =wshShell.ExpandEnvironmentStrings( "%COMPUTERNAME%" )
Next we need to open the file we want to edit into memory and then create a variable for finding and replacing the replacement text.
strText = objFile.ReadAll objFile.Close strNewText = Replace(strText, "WIN01", strComputer)
And finally, lets write the changes to the file.
Set objFile = objFSO.OpenTextFile(FileOut, ForWriting) objFile.WriteLine strNewText objFile.Close
And that’s all there is to editing a file in place with vbscript. Hope you find this useful to your situation.
Leave a Reply