Regex returning a non-capturing group?

Question

Okay, so I am new to regex, or at least to actually writing them, but here is what I have:

The string:

LDAP://CN=Doe\, John,OU=Users,DC=my,DC=domain

The regex (that is not working as expected):

(?:LDAP://CN=)([a-zA-Z]+\\?[,\s]?\s?[a-zA-Z]+)

Groups matched:

LDAP://CN=Doe\, Joe
Doe\, John

Captured group:

LDAP://CN=Doe\, John

What I want to return:

Doe, John

By my understanding (which is obviously not correct) I was under the impression that if I included ?: for a captured group it would not return it in the match; and likewise, I do not want to return \ before the , in the middle of the name – which I actually do not know how to exclude a character in a returned result as such. Anyone able to shine some light on the matter?

#

[update]

I was able to get the results being doing the following (I'm using powershell btw):

$qryResult = "LDAP://CN=Doe\, John,OU=Users,DC=my,DC=domain"  
[regex]$re = "LDAP://CN=(.*?),OU"  
$result = $re.Match($qryResult)  
(($result.Value -replace "LDAP://CN=","") -replace "\\","") -replace ",OU",""  

But it would nice to use regex from start to finish replacing the text like so. It's possible?

Answer 1

Change your PowerShell to this:

$qryResult = "LDAP://CN=Doe\, John,OU=Users,DC=my,DC=domain"  
[regex]$re = "LDAP://CN=(.*?),OU"  
$result = $re.Match($qryResult).Groups[1]
($result.Value -replace "LDAP://CN=","") -replace "\\",""

It will target only the second group (your capture group): .Groups[1]

Answer 2

You may get the required results with a single -replace:

PS> $rx = "LDAP://CN=(\p{L}+)(?:\\?,)?(\s*\p{L}+)?,OU=.*"
PS> $res = $qryResult -replace $rx, '$1$2'
PS> $res
Doe John

Details:

• LDAP://CN= - a literal character sequence
• (\p{L}+) - Group 1 capturing 1+ letters
• (?:\\?,)? - an optional sequence of an optional \ and a comma
• (\s*\p{L}+)? - an optional Group 2 capturing 0+ whitespaces and 1+ letters
• ,OU=.* - ,OU= literal char sequdnce and then any 0+ chars other than a newline symbol.