How to read and write to a file

[jimmyjmmy]

Hi,

I want to do some counting inside the file test.txt. Each time when the script is activated, the file test.txt should increase by 1. And so I wrote the undermentioned script. However the file test.txt always read 1 no matter how many times I activate the script. What have I missed?

Thanks

---------------- script ------------------

$file = FileOpen("test.txt", 2);2 = Write mode (erase previous contents)

; Check if file opened for reading OK

If $file = -1 Then

MsgBox(0, "Error", "Unable to open file.")

Exit

EndIf

$counter = FileReadLine($file);read file contents

$counter += 1

FileWriteLine($file, $counter)

MsgBox(0, "Line read:", $counter)

FileClose($file)

[jimmyjmmy]

Alright regarding the above script I found my fault and its here :-

FileOpen("test.txt", 2);2 = Write mode (erase previous contents)

I never knew that the contents of a file can be erased in the fileopen mode, I always thought that the contents of a file can only be changed in the write mode.

Moreover I also realise that if I want to read a file then write to that same file, I have to open the file to read, close that file, then reopen that same file this time to write, then close the file.

And so the script goes like this ;-

------------------- script -------------------------

$file1 = FileOpen("test.txt", 0);0 = Read mode

; Check if file opened for reading OK

If $file1 = -1 Then

MsgBox(0, "Error", "Unable to open file.")

Exit

EndIf

$counter = FileReadLine($file1);read file contents

$counter += 1

FileClose($file1)

$file2 = FileOpen("test.txt", 2); 2 = Write mode (erase previous contents)

FileWriteLine($file2, $counter)

FileClose($file2)

MsgBox(0, "Counter", "this is message " & $counter)

[PsaltyDS]

Cool. Looks like you fixed it.

You can simplify the read portion to not bother with FileOpen(), and if the file doesn't exist start a new counter from 1:

$counter = FileReadLine("test.txt", 1)
If @error Then $counter = 0
$counter += 1

Since you only read once, there is no need to code the FileOpen/FileClose cycle for read. You can FileWrite that way too, but it appends to the file by default, so to overwrite line 1 the FileOpen is required.

Edited April 21, 2007 by PsaltyDS

[jimmyjmmy]

Cool. Looks like you fixed it.

You can simplify the read portion to not bother with FileOpen(), and if the file doesn't exist start a new counter from 1:

$counter = FileReadLine("test.txt", 1)
If @error Then $counter = 0
$counter += 1

Since you only read once, there is no need to code the FileOpen/FileClose cycle for read. You can FileWrite that way too, but it appends to the file by default, so to overwrite line 1 the FileOpen is required.

Thanks a lot PsaltyDS.

Its better if FileWrite has an option to overwrite file.