Driving Applications

With WSH you can start applications. The following scripts demonstrate some of these capabilities.

Creating a Local Server Application

Some applications, such as Microsoft Word, expose objects which can be accessed programmatically. The following script uses Word's spell checker.

// JScript.
var Word, Doc, Uncorrected, Corrected;
var wdDialogToolsSpellingAndGrammar = 828;
var wdDoNotSaveChanges = 0;
Uncorrected = "Helllo world!";
Word = new ActiveXObject("Word.Application");
Doc = Word.Documents.Add();
Word.Selection.Text = Uncorrected;
Word.Dialogs(wdDialogToolsSpellingAndGrammar).Show();
if (Word.Selection.Text.length != 1) 
   Corrected = Word.Selection.Text;
else
   Corrected = Uncorrected;
Doc.Close(wdDoNotSaveChanges);
Word.Quit();

' VBScript.
Dim Word, Doc, Uncorrected, Corrected
Const wdDialogToolsSpellingAndGrammar = 828
Const wdDoNotSaveChanges = 0

Uncorrected = "Helllo world!"
Set Word = CreateObject("Word.Application")
Set Doc = Word.Documents.Add
Word.Selection.Text = Uncorrected
Word.Dialogs(wdDialogToolsSpellingAndGrammar).Show

If Len(Word.Selection.Text) <> 1 Then 
   Corrected = Word.Selection.Text
Else
   Corrected = Uncorrected
End If

Doc.Close wdDoNotSaveChanges
Word.Quit

Spawning Programs with Shell.Exec Command

The Shell.Exec command provides additional capability beyond the Shell.Run method. These abilities include:

• Improved environment variable passing

• Ability to access the standard streams of the executable

The following Visual Basic Scripting Edition (VBScript) sample demonstrates how to use standard streams and the Shell.Exec command to search a disk for a file name that matches a regular expression.

First, here's a small script that dumps to StdOut the full path of every file in the current directory and below:

' MyDir.vbs
Option Explicit
Dim FSO
Set FSO = CreateObject("Scripting.FileSystemObject")
DoDir FSO.GetFolder(".")

Sub DoDir(Folder)
   On Error Resume Next
   Dim File, SubFolder
   For Each File In Folder.Files
      WScript.StdOut.WriteLine File.Path
   Next
   For Each SubFolder in Folder.SubFolders
      DoDir SubFolder
   Next
End Sub

Next, this script searches StdIn for a pattern and dumps all lines that match that pattern to StdOut.

' MyGrep.vbs
Option Explicit
Dim RE, Line

If WScript.Arguments.Count = 0 Then WScript.Quit

Set RE = New RegExp
RE.IgnoreCase = True
RE.Pattern = WScript.Arguments(0)

While Not WScript.StdIn.AtEndOfStream
   Line = WScript.StdIn.ReadLine
   If RE.Test(Line) Then WScript.StdOut.WriteLine Line
WEnd

Together these two scripts do what we want — one lists all files in a directory tree and one finds lines that match a regular expression. Now we write a third program which does two things: it uses the operating system to pipe one program into the other, and it then pipes the result of that to its own StdOut:

// MyWhere.js
if (WScript.Arguments.Count() == 0)
   WScript.Quit();

var Pattern = WScript.Arguments(0);
var Shell = new ActiveXObject("WScript.Shell");
var Pipe = Shell.Exec("%comspec% /c \"cscript //nologo MyDir.vbs | cscript //nologo MyGrep.vbs " + Pattern + "\"");

while(!Pipe.StdOut.AtEndOfStream)
   WScript.StdOut.WriteLine(Pipe.StdOut.ReadLine());

See Also

Reference

Exec Method (Windows Script Host)

Run Method (Windows Script Host)

Other Resources

Basic Windows Script Host Tasks