How can i rewrite file with sequential file?

[Satangel]

I am going to do a project at school using sequential file to rewrite the file instead of overwrite.

What my code do is trying to wipe out my record and replace with one new variable, and how can i edit which record i like?Example like if i have three record variable,
"cats", "dogs" and "human" in my file.
How can i choose "dogs" to rename as "dogy" instead of wipe out all the data and replace just the new variable dogy?


my code reference:

in module
public names as string*50
public path as string


Private Sub cmdEditName_Click()
Dim edit As CateData
Dim filename As String
Close

path = "a:\budget2\"
filename = "cats.lst"

Open filename For Output As #1


edit.CateName = InputBox("What is the new name of the catergory", "Rename Catergory", lstExisting.List(lstExisting.ListIndex))
If Len(edit) <> 0 Then
Write #1, edit.CateName
'using listbox to show the file data
lstExisting.List(lstExisting.ListIndex) = edit.CateName

End If
cmdEditName.Enabled = False

End Sub

[kedaman]

What Output does, is just overwriting. You should instead open your file in Random or Binary, which would mean you would have to restructurize your whole file. If you want to do so i could also suggest using user defined types to contain the record data.

[Satangel]

Kedaman,
If i don't want to restucture the file mode, and i need to use sequential file mode, can i possible to do it?
coz my teacher want us to do in sequential file.
Can you told me how to do>?Thank you


[Edited by Satangel on 08-28-2000 at 08:08 AM]

[kedaman]

That depends on the file structure, you would have to post the code the reads this file, documentation on the file contents or the instruction of how the file should be structurized

[HeSaidJoe]

'here is an example of how I would change
'the content of a sequential file using an array

Private Sub command1_Click()

Dim sFileName As String
Dim sPath As String
Dim sChangeMe As String
Dim sChangeMeTo As String

'you should use the Freefile function for file numbering
'check it out in msdn
    Dim intNum As Integer
    intNum = FreeFile

    sPath = "C:\"
    sFileName = "myfile.txt"
    '
'clear the listbox
    List1.Clear
'
'variables for the record to change and what to change it to
    sChangeMe = InputBox("What is the record to change?", "Rename Item")
    sChangeMeTo = InputBox("Enter the new name for your record.", "Item Changed To")
'
'make sure you have input before acting

    If sChangeMe <> "" And sChangeMeTo <> "" Then
'
'variables for array and search
        Dim myArr() As Variant, myLine As String
        Dim iStep As Integer
        
'open your file and read it into an array

    Open sPath & sFileName For Input As intNum
        Do While Not EOF(intNum)
            iStep = iStep + 1
            ReDim Preserve myArr(1 To iStep) As Variant
            Line Input #intNum, myLine
            myArr(iStep) = myLine
           
            myArr(iStep) = Trim(myArr(iStep))
            
'add item to listbox
            List1.AddItem myArr(iStep)
            
'once you find what you are looking for change it
            If myArr(iStep) = sChangeMe Then
                myArr(iStep) = sChangeMeTo
            End If
            
        Loop
            Close #intNum
'add divider to listbox
    List1.AddItem ""
    List1.AddItem "_______________"
    List1.AddItem ""
    
'open file for rewrite of info
        Open sPath & sFileName For Output As intNum
            For iStep = 1 To UBound(myArr)
                Print #intNum, myArr(iStep)
    
'list box is for display
                List1.AddItem myArr(iStep)
            Next
        Close #intNum
Else
    MsgBox "You need information please retry!", vbCritical
    
    Exit Sub
End If
 
End Sub

Try this.

Private Sub Command1_Click()
    'Save contents to a file
    Dim Rec1 As String, Rec2 As String, Rec3 As String
    Rec1 = "Cat"
    Rec2 = "Dog"
    Rec3 = "Human"
    
    Open "Test" For Random As #1 Len = 1000
        Put #1, 1, Rec1
        Put #1, 2, Rec2
        Put #1, 3, Rec3
    Close #1
End Sub

Private Sub Command2_Click()
    'Search for Dog and change it to Doggy
    Dim Rec1 As String, Rec2 As String, Rec3 As String
    Dim iCount As Integer
    
    Open "C:\Windows\Desktop\Text.txt" For Random As #1 Len = 1000
        Do While Not EOF(1)
            iCount = iCount + 1
            Get #1, iCount, Rec1
            If Rec1 = "Dog" Then
                Put #1, iCount, "Doggy"
                Exit Do
            End If
        Loop
    Close #1
End Sub

When you press Command1, it will save Cat, Dog and Human to a file. When you press Command2, it will search for Dog and change it to doggy.