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CorNouws
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Joined: 16 Jul 2004
Posts: 16
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 Posted: Fri May 18, 2007 5:00 am Post subject: Write to a specific line in a text-file (PrivateProfileStrin |
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Hi *,
I've written a function for Replacement of READING with MsWin System.PrivateProfileString. See below.
(Info: The MsFunctions not only allows to read/write registry, bot also for ini-files)
Before submitting to the code-snippet base and such, I would like to make the story complete. Thus I start to write a function to replace WRITING with MsWin System.PrivateProfileString.
Now my question:
is there any function avaialble to write only a certain line to a text-file?
I haven't seen one in the resouces on hand, but that doesn't mean there isn't any.
Thanks for your pointers,
Cor
' | Code: | =========================================================================
' Nou&Off | 24-04-07 | www.nouenoff.nl
' Description : Replacement for READING with MsWin System.PrivateProfileString
' Arguments : Strings for File, Section and Item
' Returns : String with value found
'-------------------------------------------------------------------------
Function ConoPrivateProfileString (sFile$, sSec$, sItem$) as String
Dim n%
Dim s$, s1$
Dim bSecStart as Boolean
Dim bSecEnd as Boolean
On Error GoTo ErrorHandler
If Dir(sFile) = "" Then ' niet gevonden
ConoPrivateProfileString = ""
Exit Function
End If
sSec= "["& sSec & "]"
n = FreeFile()
Open sFile for Input As #n
Do while NOT EOF(n)
Input #n, s
If NOT bSecStart Then
If Left (s, len(sSec)) = sSec Then
bSecStart = true
End If
Else
If Left (s, len(sItem)) = sItem Then
s1 = Right (s, (len(s) - len(sItem)-1))
Exit Do
ElseIf s = "" Then
Exit Do
End If
End If
Loop
Close #n
ConoPrivateProfileString = s1
Exit Function
ErrorHandler:
MyErrMessenger ("ConoPrivateProfileString")
End Function
Sub MyErrMessenger (s$)
msgBox "Error in " & ConoPrivateProfileString & " :" & CHR(13) & CHR(13)_
& Error() & CHR(13) & "on line: " & Erl, 16, SMSGTITEL
End Sub |
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pitonyak
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Joined: 09 Mar 2004
Posts: 3618
Location: Columbus, Ohio, USA
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| Posted: Sat May 19, 2007 5:38 pm Post subject: |
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I do not believe that any function exists for this, which makes sense if you think about it. The file routines do not allow an insertion. Probably the best you can do is to read data until you get to a specific line number. At that point, the line uses a specific number of bytes. If you write exactly the same number of bytes and over-write the lines, you are fine. If not, then you must literally copy the file, or, read the rest of the data and shift it to make room for more. Similar issue if you write less data than currently exists.
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Andrew Pitonyak
http://www.pitonyak.org/oo.php |
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levan82
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Joined: 14 Jul 2006
Posts: 33
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| Posted: Wed Jun 13, 2007 1:11 pm Post subject: |
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CorNouws
this code takes very long time to get data from ini-files, when there are many keys in it.
Is there any other way to access ini file info?
thanks a lot in advance |
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pitonyak
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Joined: 09 Mar 2004
Posts: 3618
Location: Columbus, Ohio, USA
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| Posted: Thu Jun 14, 2007 10:49 am Post subject: |
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You can optimize the code if needed. For example, "If NOT bSecStart Then" is true only once, so move this out of the loop.
There are other obvious optimizations, such as calculating Len(sItem) every time it is used. This is wasteful in the extreme.
Finally, I am not convinced that this code is absolutely accurate, based on a cursory look. For example, what is the format of an INI file and what are valid values for sItem? What if you search for a key named "hello.one" and the key "hello.one.two" is also contained in the file. What is returned?
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Andrew Pitonyak
http://www.pitonyak.org/oo.php |
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levan82
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Joined: 14 Jul 2006
Posts: 33
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| Posted: Sat Jun 16, 2007 2:51 pm Post subject: |
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pitonyak
please tell me more accurate code if you can?  |
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pitonyak
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Joined: 09 Mar 2004
Posts: 3618
Location: Columbus, Ohio, USA
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| Posted: Sat Jun 16, 2007 9:32 pm Post subject: |
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For example, here are a few changes, staying with the spirit of the existing code:
| Code: | REM First, change the arguments to values because they are changed in the method.
Function ConoPrivateProfileString2(ByVal sFile$, ByVal sSec$, ByVal sItem$) as String
Dim n%
Dim s$, s1$
Dim bSecStart as Boolean
Dim bSecEnd as Boolean
On Error GoTo ErrorHandler
If Dir(sFile) = "" Then ' niet gevonden
ConoPrivateProfileString2 = ""
Exit Function
End If
sSec= "["& sSec & "]"
n = FreeFile()
Open sFile for Input As #n
REM Find the proper section.
REM Do this outside the loop so that it will be faster
Dim nSecLen As Integer
nSecLen = len(sSec)
Do while NOT EOF(n)
Input #n, s
REM InStr is probably faster than using Left
If InStr(s,sSec) = 1 Then
'If Left (s, nSecLen) = sSec Then
bSecStart = true
Exit Do
End If
Loop
REM Never found it, get out!
If NOT bSecStart Then
Close #n
Exit Function
End If
REM The code assumes that it is followed by an equal sign and that there are
REM no spaces. OK, lets assume that. Append an '=', which makes this safer.
sItem = sItem & "="
nSecLen = len(sItem)
Do while NOT EOF(n)
Input #n, s
If InStr(s, sItem) = 1 Then
'If Left (s, nSecLen) = sItem Then
s1 = Right (s, (len(s) - nSecLen))
Exit Do
ElseIf s = "" Then
Exit Do
End If
Loop
Close #n
ConoPrivateProfileString2 = s1
Exit Function
ErrorHandler:
MyErrMessenger ("ConoPrivateProfileString")
End Function
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On my sample INI file that I created, the time went from 4.8 system ticks to 4.1 system ticks.
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Andrew Pitonyak
http://www.pitonyak.org/oo.php |
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levan82
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Joined: 14 Jul 2006
Posts: 33
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| Posted: Sun Jun 17, 2007 3:42 am Post subject: |
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thanks pitonyak it is a littte faster, but still very slow
thanks anyway  |
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