vbscript Eval a string to a Variable in a loop? - string

Question

I am trying to use vbscript's Eval (or maybe I need Execute) to create some variables from the key names from an ini file. The ini file can have unlimited unknown key=val pairs. I need to create a variable based on the key name no matter what.
Ini File contents:
myPath=c:\test
myExe=myapp.exe
....
xxx=123
yyy=abc
My code that reads the ini and returns the key and values to an object
The code I am trying to get working is here:
For each pair in objINI
Eval("pair.key=pair.val")
Next
msgbox myPath
msgbox myExe
But both msgbox's are showing empty
And yes I am sure pair.key and pair.val have the correct values.
Thoughts on what I am missing or if this is even possible?

Answer 1

You need to Execute (an assign statement), not to Eval(uate a boolean expression):
>> n = "Name"
>> v = "Value"
>> WScript.Echo TypeName(Eval("n=v"))
>>
Boolean
>> Execute "n=v"
>> WScript.Echo n
>>
Value
>>
From the docs:
In VBScript, x = y can be interpreted two ways. The first is as an
assignment statement, where the value of y is assigned to x. The
second interpretation is as an expression that tests if x and y have
the same value. If they do, result is True; if they are not, result is
False. The Execute statement always uses the first interpretation,
whereas the Eval method always uses the second.
(This does not mean you should do such things; neither at home, nor at work)

Answer 2

You eval'd the literal code pair.key = pair.value.
That assigns to pair.key.
You want to assign to the value of pair.key – if pair.key is myPath, you want to eval myPath = pair.value.
You can do that by concatenating strings:
Execute(pair.name + " = pair.value")

Answer 3

If you want to read key/value pairs from an INI file you'd be better off storing them in a dictionary. I wrote a function for this some years ago. Basically looks like this:
Function ParseIni(filename)
Set ParseIni = Nothing
Set config = CreateObject("Scripting.Dictionary")
section = ""
Set file = CreateObject("Scripting.FileSystemObject").OpenTextFile(filename)
Do While Not file.AtEndOfStream
line = Trim(Replace(file.ReadLine, vbTab, " "))
If InStr(line, ";") > 0 Then line = Trim(Left(line, InStr(line, ";") - 1))
If line <> "" Then
If Left(line, 1) = "[" And Right(line, 1) = "]" Then
' line is a section name
section = Trim(Mid(line, 2, Len(line) - 2))
If section = "" Then _
WScript.Echo "Parse Error: section name is empty string."
If config.Exists(section) Then _
WScript.Echo "Parse Error: duplicate section name '" & name & "'."
config.Add section, CreateObject("Scripting.Dictionary")
ElseIf InStr(line, "=") > 0 Then
' line is a parameter line
If section = "" And Not config.Exists(section) Then _
config.Add section, CreateObject("Scripting.Dictionary")
param = Split(line, "=", 2)
param(0) = Trim(param(0))
param(1) = Trim(param(1))
If param(0) = "" Then _
WScript.Echo "Parse Error: invalid parameter name '" & param(0) & "'."
If param(1) = "" Then param(1) = True
config(section).Add param(0), param(1)
Else
' line is neither parameter nor section name, thus invalid
WScript.Echo "Parse Error: expected parameter definition in line '" _
& line & "'."
End If
End If
Loop
file.Close
Set ParseIni = config
End Function