Is this bug in File I/O

[GURU_PANDIAN]

Access Write only

Performed Read only but not displayed the data

not throwing any error (error 😎

When I wire Indicator on read out it throws an error 8.

why such things?

Please help me to get clear out of this.

 File Chosen during Runtime

[crossrulz]

If you are not using the output, then is it likely that the read portion was not actually done.  This is common in many other LabVIEW primitives that parts of a primitive are not performed because the output is not used.

But a bug?  I would say so.

[JensG69]

The LabVIEW compiler does a lot of optimization in the background nowadays. It's very likely for your first picture that the read-vi is completely removed since no output is used thus not throwing an error at all.

Bug? Yes, kind of

Regards, Jens

[GURU_PANDIAN]

If the Read VI is completely removed then how ref number if passed to close file?

I have checked by highlight execution.

It passes data and follows data flow...

[JensG69]

Did you read the whitepaper about the compiler? Of course in the background, the file refnum will be reconnected betweeen file open and file close. On the other hand it might even be that even the file open and file close is removed before the compilation. It's difficult to predict what's going in the background. This will also not reflect the dataflow you see in highlight execution mode.

Just to make it clear: I'm speculating, I'm not 100% sure that the read-vi is really removed by DFIR optimazition but it does at least explain the difference between your two code snippets.

Regards, Jens

[billko]

LOL it's like you caught the compiler with its pants down.  😄

[JensG69]

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@billko wrote:

LOL it's like you caught the compiler with its pants down.  😄

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[GURU_PANDIAN]

Yeah

I understood that u are the only one genious in LabVIEW.

But Remember I am a learner towards certification.

So i need to taken care about all the points.

by time passes everything will change. let see...

Thanks for your genious comment

[billko]

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@GURU_PANDIAN wrote:

Yeah

I understood that u are the only one genious in LabVIEW.

But Remember I am a learner towards certification.

So i need to taken care about all the points.

by time passes everything will change. let see...

Thanks for your genious comment

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Thanks for not quoting who you were responding to, so no one knows who should be the honorable recipient of your genius comment.  If you were actually responding to me, I was just trying to show that nowadays, it's pretty hard to catch LabVIEW doing something inconsistent like that, because there are decades of people like yourself catching all the little oddities like this.  I thought it was pretty cool, actually.