VB.Net: Regular Expressions - regex

Question

I'm creating an application that will be able to tell me who is logged onto what PC, in the manufacturing center, where I work.
I'm using psexec's psloggedon cmd process to get me the information for me and a VB.net windows application to show me the information.
I begin by first querying a databse for all the PC's we currently have active and dumping the data into a datagridview object. (Shown below)
Private Sub Button(sender As System.Object, e As System.EventArgs) Handles btngetPC.Click
'GET AREAS FROM DATABASE
Dim ds As New DataSet()
Dim db As String = "QUERY STRING GOES HERE"
'CONNECT TO DATABASE
Using da As New SqlDataAdapter(db, MySQLConnection)
da.Fill(ds, "MACHINE_NAME")
End Using
With datagridView1
.DataSource = ds.Tables("MACHINE_NAME")
End With
'ADD COLUMN TO DATAGRIDVIEW
datagridView1.Columns.Add("LOGGED_IN", "LOGGED_IN")
MySQLConnection.Close()
End Sub
Once I have my datagridview object filled out with all my active PC's, I can then use the machine names to run the psloggedon cmd to get who is logged in. I do so by using:
Private Sub execute(sender As Object, e As EventArgs) Handles bntExecuteCmd.Click
'COUNT ENTRIES
Dim RowCount As Integer = datagridView1.RowCount
''EXECUTE CMD
For i = 0 To RowCount - 2
'PERFORM PSLOGGEDON ROUTINE
Dim Proc1 As New Process
Proc1.StartInfo = New ProcessStartInfo("psloggedon")
Proc1.StartInfo.Arguments = "-l \\" & datagridView1.Rows(i).Cells(1).Value & ""
Proc1.StartInfo.RedirectStandardOutput = True
Proc1.StartInfo.UseShellExecute = False
Proc1.StartInfo.CreateNoWindow = True
Proc1.Start()
If Not Proc1.WaitForExit(300) Then
Proc1.Kill()
End If
'INSERT RESULTS INTO LOGGEN_IN COLUMN
Dim msg As String = Proc1.StandardOutput.ReadToEnd
Dim idx As Integer = msg.LastIndexOf("\"c)
Dim user As String = msg.Substring(idx + 1)
Dim final As String = UCase(System.Text.RegularExpressions.Regex.Replace(user, "^ELP.*$", ""))
datagridView1.Rows(i).Cells(2).Value = final
Next
End Sub
Finally, here is my question:
To get the employee names I must use regex becuase the raw format is unacceptable.
raw format:
"Connecting to Registry of \ELPSC171698...
Users logged on locally:
ECHOSTAR\Jane.Doe"
format after applying:
'INSERT RESULTS INTO LOGGEN_IN COLUMN
Dim msg As String = Proc1.StandardOutput.ReadToEnd
Dim idx As Integer = msg.LastIndexOf("\"c)
Dim user As String = msg.Substring(idx + 1)
Dim final As String = UCase(System.Text.RegularExpressions.Regex.Replace(user, "^ELP.*$", ""))
datagridView1.Rows(i).Cells(2).Value = final
"PAULA.RODRIGUEZ"
Looks good, right? However, when the raw format has more than one associate, like so:
"Connecting to Registry of \ELPSC173068...
Users logged on locally:
ECHOSTAR\John.Doe
ECHOSTAR\Ben.Doe"
the code I have written will get me the last person in this list. In this case, I will get JOHN.DOE when I need to get BEN.DOE.
Now the question: How can I change this code:
'INSERT RESULTS INTO LOGGEN_IN COLUMN
Dim msg As String = Proc1.StandardOutput.ReadToEnd
Dim idx As Integer = msg.LastIndexOf("\"c)
Dim user As String = msg.Substring(idx + 1)
Dim final As String = UCase(System.Text.RegularExpressions.Regex.Replace(user, "^ELP.*$", ""))
datagridView1.Rows(i).Cells(2).Value = final
To get me the first person, "JOHN.DOE" from here:
"Connecting to Registry of \ELPSC173068...
Users logged on locally:
ECHOSTAR\John.Doe
ECHOSTAR\Ben.Doe"
I hope my question was clear and well constructed. Thank you.

Answer 1

Use more specific regex and a capture group to get multiple items.
Dim mc As MatchCollection = Regex.Matches("Users logged on locally: ECHOSTAR\John.Doe ECHOSTAR\Ben.Doe", "[\t ]+[a-z_0-9]+\\(?<n>[a-z_\.0-9]+)(([\t ])|($))", RegexOptions.ExplicitCapture Or RegexOptions.IgnoreCase Or RegexOptions.Multiline)
For Each m As Match In mc
Dim name As String = m.Groups("n").value
Next
if you just want the first one then...
If mc.Count >= 1 Then
Dim name As String = mc(0).Groups("n").Value
End If

Answer 2

Change
Dim idx As Integer = msg.LastIndexOf("\"c)
to
Dim idx As Integer = msg.IndexOf("\"c)
Alternatively consider this:
Assuming you've validated the string first.
Dim user As String = msg.Split({"\"c, " "c}, StringSplitOptions.RemoveEmptyEntries)(1) _
.Replace("."c, " "c).ToUpper
To leave the decimal in just remove .Replace("."c, " "c)