Set File Position Method

The Set File Position method sets the position of the next read or write operation in an open file. It does not return a value. If you write to a file after reading beyond the end of the file, then this method increases the file length. If a read operation attempts to specify a negative or zero position, then Visual Basic returns an error message.

Format

Seek [#]filenumber, position

The following table describes the arguments that you can use with this method.

Argument	Description
filenumber	The file number that the Open statement uses to open the file. For more information, see Open File Method.
position	An expression of type long that identifies the position depending on the following mode that this method uses to open the file: Random mode. The position of a record number. Other modes. The position of the byte offset. The position is in the range of 1 through 2,147,483,647. The first byte or record in the file is at position 1, the second is at position 2, and so on.

Example

The following example reads the contents of a sequential file line by line to a carriage return, and then displays the results. The CreateFile subroutine creates the c:\temp001 file that the main subroutine uses:

(general) (declarations)
Option Explicit
Declare Sub CreateFile

Sub CreateFile
   Rem Put the numbers 10-100 into a file
   Dim x as Integer
   Open "c:\temp001" for Output as #1
   For x = 10 to 100 step 10
      Write #1, x
   Next x
   Close #1
End Sub

Sub Button_Click
   Dim testscore as String
   Dim x
   Dim y
   Dim newline
   Call CreateFile
   Open "c:\temp001" for Input as #1
   x = 1
   newline = Chr(10)
   msgtext = "The test scores are: " & newline
   Do Until x = Lof(1)
      Line Input #1, testscore
      x = x + 1
      y = Seek(1)
      If y>Lof(1) then
         x = Lof(1)
      Else
         Seek 1,y
      End If
      msgtext = msgtext & newline & testscore 
   Loop
   Close #1
      Kill "c:\temp001"
End Sub