Using Filter() using something similar to RegEx

**Rhudi** · 11-14-2014, 01:27 PM

I have a line that looks like this:

     BGPlocalAS = Join(Filter(BGPNeighbor, " neighbor " & currentNeighborIPArray(x) & " local-as "), "")     ' local-as

The trouble is, the lines I'm looking for may start as either:
"_neighbor ..." (one beginning space) or
"__neighbor ..." (two beginning spaces) (I had to use "_" to make it look right)

Using RegEx, this is easy. "^_neighbor " matches the one-space line, where "^__neighbor " would match the two-space line.

Right now, my idea is to build an array filtering on " neighbor ", then count through that array twice. The first time, I will compare left(BGPLocalAS,3) = "_ne". The second time, left(BGPLocalAS,3) = "__n".

Is there a way to make Filter() pattern-match like RegEx does, or should I just do my twice-loop thing? There would never be more than about 20ish lines in my array.

I think I'm looking for elegant vs brute force.

**Kyle123** · 11-14-2014, 01:46 PM

Loop through twice, it'll be quicker

than using Regex, not that you could with filter anyway...

**Rhudi** · 11-18-2014, 05:38 PM

Thanks. I currently do this:

    For zz = LBound(rSRCDataArray) To UBound(rSRCDataArray)
        rSRCDataArray(zz) = "!" & rSRCDataArray(zz) & "!" ' wrap delimiters to cure false matches ( since I do not know how to do RegEx yet)
        ' For example, searching for "vrf " will find "vrf " and " vrf "
        '                            "!vrf " will not find "! vrf "
        '                            " encapsulation ###" will find second-dot1q entries if present
        '                            " encapsulation ###!" will find only the encap without second-dot1q
    Next zz

As you might guess, I'm using this to open a "show run" router dump. I've already dealt with the limitation of Application.MAtch if my text file is too big.

Here is how I find the correct interface (which is supposed to match a cell on my worksheet:

    Range("B2").Select
    rSRCIntArray = Filter(rSRCDataArray, "!interface " & ActiveCell.Value & "!") ' Match data array on specified interface
    If Not UBound(rSRCIntArray) = 0 Then
        Beep
        Call MarkPaleRED
        MsgBox "CRITICAL ERROR!" & vbCrLf & "interface " & ActiveCell.Value & vbCrLf & "   not found in data!"
        End
    Else
        Call MarkPaleGREEN
    End If

If you know anything about Cisco routers, you notice that looking for the interface the way I do with the bangs ("!") is silly, but for other searches I'm being consistent.

Plus, for other things (like vrf or ip route, etc) I would use the bangs to help search for proper start/end of line hits.

In BGP code, I might looks for "! neighbor " which is different than "! neighbor".
In a static route, I would Filter for a gateway IP at the end of a line, similar to " 42.68.101.12!".
If I were looking for a matching neighbor, I'd Filter for "! neighbor 42.68.101.12" or "! neighbor 42.68.101.12".

For something like an "ip route" I Filter using the IP ending with a bang, then use a For/Next on LBound/UBound on the Filter results to match lines that start "!ip route" (and if looking for public routes, skipping "!ip route vrf".

Instead of using ReDim, I tend to Join and array into a delimited string, the Split it back to a correctly sized array.