More reliable check for file

[Jdr]

I'm trying to check for the existance of a file, on logon the file is there, then gets deleted and after a while recreated. I'm using this code:

Sleep(100)
        If not FileExists($sFile) Then
            Sleep(150)
               If FileExists($sFile) Then
                    GUICtrlSendToDummy($iDummy)

What happens is this: 

1. User logs on, the file is present, or at least it usually is
2. After about 10 seconds the file gets deleted
3. Then after about 50 seconds the file gets created again, this is when I need the check, because now the process is finished.

The above code is part of a pretty long do....until false loop running an animation.

The problem is that sometimes this code fails. Without the sleep statements it didn't work at all so I think this is a timing issue. Pretty primitive code I admit, there must be a better way...

 

Edited August 19, 2016 by Jdr
typo

[Jos]

So you currently wait 100Ms (0.10 second) initially, then test for the file and then 150Msecs later you test it again?

Jos

[orbs]

if i get this right, then you need to play some animation while your script is waiting for the file to re-appear?

well, you can delegate the animation to an external process, and make your waiting loop a lot simpler:

; create the animation
While Not FileExists($sFile)
    Sleep(100)
    ; check for user clicking a cencellation button
WEnd

 

Edited August 19, 2016 by orbs

[Jdr]

1 hour ago, Jos said:

So you currently wait 100Ms (0.10 second) initially, then test for the file and then 150Msecs later you test it again?

Jos

Yes, I admit that's pretty fast, basically it's constantly checking for the file

[Jdr]

1 hour ago, Jos said:

So you currently wait 100Ms (0.10 second) initially, then test for the file and then 150Msecs later you test it again?

Jos

Yes, I admit that's pretty fast, basically it's constantly checking for the file

[Jdr]

45 minutes ago, orbs said:

if i get this right, then you need to play some animation while your script is waiting for the file to re-appear?

well, you can delegate the animation to an external process, and make your waiting loop a lot simpler:

; create the animation
While Not FileExists($sFile)
    Sleep(100)
    ; check for user clicking a cencellation button
WEnd

 

Yes, that's what happens. Won't  "While Not" miss the beginning when the file is there? How can I get around that?

[orbs]

24 minutes ago, Jdr said:

Won't  "While Not" miss the beginning when the file is there?

the real problem is that you have a single indication (the existence of a file) for two scenarios: before the process begins, and after the process ends. you better come up with a more precise distinction. you can, of course, do this:

; create the animation

; wait for first instance of the file to disappear
While FileExists($sFile)
    Sleep(100)
WEnd

; ok, the first instance disappeared. now wait for the second instance to appear
While Not FileExists($sFile)
    Sleep(100)
    ; check for user clicking a cencellation button
WEnd

but, you must be absolutely sure that your script runs before the second instance appears! if you miss that, your script will hang at the 1st loop, and never reach to an end.

Edited August 19, 2016 by orbs

[aleph01]

If, per Orbs, you have to be sure your script runs, you may be able to use ProcessExists in a couple of loops to wait for your process to start then stop, one to wait for the script to start running, one to wait for the script to finish.