(VB6) Reading text files line by line looking for specific words

Question 1

Here's a function you could use to load the contents of a file:

Public Function LoadFile(dFile As String) As String

    Dim ff As Integer

    On Error Resume Next

    ff = FreeFile
    Open dFile For Binary As #ff
        LoadFile = Space(LOF(ff))
        Get #ff, , LoadFile
    Close #ff

End Function

Next, you want to split the output of that file. First, you will need to know what type of EOL termination character will be produced by the back-end. Assuming each line ends with a carriage return (13) and a line feed (10), you could use this code to store each line into a string array:

Dim lines() As String
lines = Split(LoadFile("LANrealm.log"), vbCrLf)

Finally, it's a matter of cycling through each line (using a For...Next loop) and look for whatever information you want to extract:

For i = 0 To Ubound(lines)
    ' Add here necessary logic to extract the information.
    ' Each line can be accessed by indexing the array as: lines(i)
Next

Hope this helps you get started...

To test the code:

Start VB6 and create a new project. VB6 will create an empty project with one form
Double click the form to view it
Right click the Toolbox and select "Components"
Locate the "Microsoft Common Dialog Control" and select it
Click OK
Now, drag the "CommonDialog" component from the Toolbox onto the form
Double click the form to view its source code
Paste the following code

NOTE: Make sure you overwrite any pre-existing code

Option Explicit

Private Sub Form_Load()
    cDlg.DefaultExt = "txt"
    cDlg.Filter = "Text Files|*.txt;*.log"
    cDlg.ShowOpen

    If cDlg.fileName <> "" Then AnalyzeFile .fileName
End Sub

Private Sub AnalyzeFile(fileName As String)
    Dim fileContents As String
    Dim lines() As String
    Dim i As Integer

    fileContents = LoadFile(fileName)
    lines = Split(fileContents, vbCrLf)

    For i = 0 To UBound(lines)
        If InStr(1, lines(i), "event:", vbTextCompare) Then
            MsgBox "Line #" & i & " contains the string 'event'" + vbCrLf + vbCrLf + lines(i)
        End If
    Next
End Sub

Private Function LoadFile(dFile As String) As String
    Dim ff As Integer
    On Error Resume Next

    ff = FreeFile
    Open dFile For Binary As #ff
        LoadFile = Space(LOF(ff))
        Get #ff, , LoadFile
    Close #ff
End Function

Run the program and, when asked to supply a file, select one of the logs that will be generated by the back-end.

In this example, the program will tell you which lines contain "event information", such as "Event: Roper killed Pleb (M4A1) shots=5 Feet=2 Body=2 Head=1".

Question 2

One problem I would see doing this in real-time, reading and writing is if two or more computers or apps try to open the same file. This could be a bit of a mess.

Question 3

Ok, so if you REALLY want to read your file line by line, I would change your logfile a little different.

******************
LANrealm Match Log
******************

Game:  Call of Duty 4
Game Type:  Team Deathmatch
Date: 01-Jan-2013
Time:1 9:00:00
Players: Tramp, Roper, d00b, Pleb
Score Limit:    150

Event:  Game Start  
Event:  Roper killed Pleb (M4A1) shots=5 Feet=2 Body=2 Head=1 
Event:  Tramp committed suicide (Fall damage)
Event:  Tramp killed d00b (Grenade)
Event:  Pleb said "I'm saying something"
Event:  Pleb teamkilled d00b (G3) shots=3 Feet=0 Body=2 Head=1 
Event:  Game Finished

Winner: Roper

Stat: Roper Kills=1,Deaths=0,Suicides=0,Teamkills=0
Stat: Tramp Kills=1,Deaths=0,Suicides=1,Teamkills=0
Stat: Pleb Kills=0,Deaths=0,Suicides=0,Teamkills=1
Stat: d00b Kills=0,Deaths=0,Suicides=0,Teamkills=0

You can use this to read the file line by line.

   Dim FileNo As Integer
   Dim TempData As String
   Dim TempStr As String
   FileNo = FreeFile
   Open "c:\game.log" For Input As FileNo
      Do
         Line Input #FileNo, TempStr
         TempData = TempData & TempStr or do what ever you want it to do with that line.
         DoEvents
      Loop Until EOF(FileNo)
   Close #FileNo
   MsgBox TempData

However, I would suggest to read the whole file into a string, and then parse out info you want. If you did, you can then pick out info you might want, like name of game etc.....

Try this. Create a new module, and paste this in it.

Public Function ParseData(DataSTR As String, StartSTR As String, EndSTR As String) As String
   Dim Split1
   Dim Split2
   Split1 = Split(DataSTR, StartSTR, , 1)
   Split2 = Split(Split1(1), EndSTR, , 1)
   SplitParse = Split2(0)
End Function

Then add this to a command button.

Private Sub Command2_Click()
 Dim FileNo As Integer
   Dim TempData As String
   FileNo = FreeFile
   Open "c:\game.log" For Input As FileNo
      TempData = Input(LOF(FileNo), FileNo)
   Close
   MsgBox TempData
   MsgBox Trim(ParseData(TempData, "Game:", Chr(10)))
End Sub

Now this is just a sample of what you can do.