Wildcards and/or Regular Expressions

[yablonka]

Hi all,

Im trying to create a very simple procedure in VB.NET that gets a string and gives back a boolean indicating if the string matches a certain template. For example...

if the string is: abcdefg
and the template is: *cd?f*
(* indicates zero or multiple characters and ? indicates a single character)
then in this case the string does match the template.

Im trying to mess around with regular expression unsuccesfully.

Anyone?
(A sample code will be very helpful)
Thanks.

 

[themster]

By using a parser you can build a regular expression from the template.

The template symbol * equals \w* in regex and ? equals \w.

Then try this:

Dim Template As String
Dim Pattern As String
Dim SearchString As String
Dim FoundMatch As Boolean
Dim i As Integer
Dim r As Regex

Template = "*cd?f*"
SearchString = "abcdefg"

For i = 0 To Len(Template) - 1
    Select Case Template.Substring(i, 1)
        Case "*"
            Pattern = Pattern + "\w*"
        Case "?"
            Pattern = Pattern + "\w"
        Case Else
            Pattern = Pattern + Template.Substring(i, 1)
    End Select
Next

FoundMatch = r.IsMatch(SearchString, Pattern)

In this case the regex pattern becomes \w*cd\wf\w* and the string matches the template.