WEB LISTING 2: Which.vbs
BEGIN COMMENT
' VBScript file to tell you where in your path the first and subsequent 
' instances of an executable are.

' Created by GFC 2002.02.20.
END COMMENT

On Error Resume Next

set objCmdArgs = WScript.Arguments

If objCmdArgs.Count < 1 Then
	Usage()
End If

intStart = 0

If LCase(objCmdArgs(0)) = "-a" Then
	If objCmdArgs(1) = "" Then
		Usage()
	End If
	strAll = "Yes"
	intStart = 1
End If

ExtCheck(objCmdArgs(intStart))

set objShell = WScript.CreateObject("WScript.Shell")
set objFS = WScript.CreateObject("Scripting.FileSystemObject")

strPath = objShell.ExpandEnvironmentStrings("%PATH%")
strPath = strPATH & “:.”
strEXT = objShell.ExpandEnvironmentStrings("%PATHEXT%")

arrEXT = Split(strEXT,";")
arrPATH = Split(strPATH,";")

strFound = "No"

For a = 0 to UBound(arrPATH)
	For b = 0 to UBound(arrEXT)
		strFile = arrPATH(a) & "\" & objCmdArgs(intStart) & arrEXT(b)
		If objFS.FileExists(strFile) Then
			WScript.Echo LCase(objCmdArgs(intStart)) & UCase(arrEXT(b)) & " is in: " & 
arrPATH(a)
			strFound = "Yes"
			If strAll = "" Then
				WScript.Quit 0
			End If			
		End If
	Next
Next

If strFound = "No" Then
	WScript.Echo "<" & objCmdArgs(intStart) & "> is not anywhere in the PATH."
End If

set objCmdArgs = Nothing
set objShell = Nothing
set objFS = Nothing

WScript.Quit 0

Function ExtCheck(strArg)
	set objRegExp = New RegExp
BEGIN COMMENT
' I've never seen an executable with numbers in the extension, but if so...
	' objRegExp.Pattern = "\.[a-z,0-9]{3}$"
END COMMENT
	objRegExp.Pattern = "\.[a-z]{3}$"
	objRegExp.IgnoreCase = True
	set collEXTMatch = objRegExp.Execute(strArg)
	If collEXTMatch.Count <> 0 Then
		Usage()
	End If
	set collEXTMatch = Nothing
	set objRegExp = Nothing
End Function

Function Usage()
	WScript.Echo vbCrLf & "Usage: which [-a] command-to-find" & vbCrLf & vbCrLf & "Note:" & 
vbCrLf & "Do *not* enter any EXTension"
	WScript.Quit 1
End Function