Variable (sometimes) not recognized as array

[LeaningCactus]

Hi all,

I am encountering a strange error in my script. To focus the problem, it is in a section that imports a file into an array variable using:

_FileReadToArray("c:\... \battery_info.out", $bat).

where $bat is defined earlier as a local variable, with no array designation [ ]. Later on I pose a conditional:

If $bat[17]="some text" Then

...

At this point, when I run the program, it sometimes recognizes $bat as an array, and sometimes it tells me that $bat is not an array, so I cannot couple it with [17]. Usually I run the program once, get the error message (program crashes), run again and it works fine. If there are a few minutes in between tries, I get the error again, even if the computer hasn't restarted.

What might cause this behavior?

Thanks!

[jchd]

Without having a chance to look at a failing reproducer or actual code, it'll be very hard to say.

Wild guess: you use $bat = some_function_returning_array(whatever) but this function sometimes fails and $bat is then not an array.

Use error checking to avoid that kind of situation.

[water]

Use error checking after _FileReadToArray. If this command fails $bat will still be a simple variable. If you then try to acces the variable as an array you get an error.

[LeaningCactus]

Hi guys,

thanks for your comments.

I didn't post the entire code because it is pretty long (in my perspective...), and much of it deals with GUI stuff.

A little elaboration: I am running some lab experiments that include pressurized vessels with in-situ pH probes. The data is stored in a Campbell Scientific Datalogger, and can be retrieved to an actual file on a computer only manually, through a free Campbells Scientific program. If you want the retrieving to be automated, you need to pay >$700 for their fancy software.

So instead I found out about AutoIt a few weeks ago and wrote a program that retrieves the data automatically every 30 seconds (while 1 loop), and plots the last data up to 12 hours back. It is also designed to send me a text message to my phone if there is pressure loss or if the power goes out in the lab (lab laptop's battery is discharging).

The actual battery status check is done through an external VBS script that produces an output file with a bunch of lines. This output file is then imported into my program, into $bat, using the command:

_FileReadToArray("c:\... \battery_info.out", $bat)

and:

If $bat[17] = " Discharging = True" Then

[start alert procedure, send text message, bla bla bla]

EndIf

Again, $bat is not used at any point prior to the loop, it is only declared as "Local $bat"

What I don't understand is why the program sometimes works and sometimes doesn't. I guess I'm not looking only to eliminate the problem but also to understand why it happens for future works. I can publish the enitre code, if it helps, but since it was not designed for a commercial project it is fairly ugly (structurally).

....

...

...

Oh, wait... The problem may not be with AutoIt, but with the script that checks for the battery status. I think there is some sort of a delay from the time of check to the time of print (of output file), which may cause the error. I'll get back to you on that...

Thanks again!

[LeaningCactus]

Ok fellas, figured out what the problem was.

It wasn't the external script that checks for the battery status, but rather the command from AutoIt that ran it. I used:

RunWait("C:...cscript battery_info_no_echo.vbs //NoLogo")

This sometimes caused the VBS script not to run at all, and therefore no actual file was imported into $bat, which cause the array error. I wondered if the VBS script was not running sometimes becasue cscript is an integral part of Windows, and is actually some sort of a DOS command. So I switched to:

RunWait(@ComSpec & " /c " & "cscript battery_info_no_echo.vbs //NoLogo")

And now it runs great.

Thanks guys for your willing to help.

As an AutoIt newbie I must say that the AutoIt online documentation is superb. I often find myself finding a useful function while searching for another function that does something similar but not quite.