FileGetPos question

[polps]

Hello all.
 
I'm facing an odd situation with FileGetPos statement.
 
Referring to the following simple code
 
 

; Autoit version 3.3.8.1

$file = "file.txt"
$ofile = FileOpen ( $file, 0 )
While 1
   $pos = FileGetPos ( $ofile )
   $line = FileReadLine ( $ofile )
   If @error Then ExitLoop
   msgbox (0,0, $pos )
WEnd
FileClose ( $ofile )

 and this simple TXT file with only 3 records as example

first line
second line
third line

I espected taht - for each loop - $pos showed me the current line number (from 0 to 2);

Instead $pos increase in a strange way getting - for each loop - the values 0, 12, 25.   Why?

Can anyone help me?

Thanks!

Gianluca

[FireFox]

Hi,

The offset is NOT the line number, it's the position of the stream and one offset corresponds to a character in the file.

Edit : FYI the "new line" is a character.

Br, FireFox.

Edited February 26, 2014 by FireFox

[polps]

Thanks firefox.

So, when I parse the file, how to retrive the current line number?

[FireFox]

It depends on how do you want to parse the file, by line?

FileReadLine has a parameter to read the line you want.

Br, FireFox.

[polps]

I would parse the file from the beginning with FileReadLine in a loop

I search a determined string with StringInStr

If the current line contains the searched string, I would retrieve the current line number, and move backward a certain number of line (with FileSetPos)

now I am understanding that there is no a direct method to retrieve the current line number and to move up or down scrolling the files...

may be I have to find a workaround.

thanks again

[FireFox]

Well, if you use FileReadLine it's you who gives the line number so it's explicit that you know it through a variable.

#include <File.au3>
For $i = 1 To _FileCountLines("toto.txt")
    ;the file line number is $i
    ConsoleWrite(FileReadLine("toto.txt", $i) & @Lf)
Next

Br, FireFox.

[polps]

yes, undestood.

Thanks a lot.

Br

Gianluca.

[BrewManNH]

I would do it this way, then you're not parsing the script twice, and you're not using the line number parameter in FileReadLine, because if the file is large it's going to be very slow.

 

$file = "file.txt"
$ofile = FileOpen($file)
Global $pos = 1
While 1
    $line = FileReadLine ( $ofile )
    If @error Then ExitLoop
    msgbox (0,0, $pos )
    $pos += 1
WEnd
FileClose ( $ofile )