LabVIEW Minutiae (that may bite you someday)

[Darren]

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@for(imstuck) wrote:

file or folder exists returns TRUE on an empty path.

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As documented. 😉

[GregFreeman]

"Is there some computing reason for this?"

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@Darren wrote:

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@for(imstuck) wrote:

file or folder exists returns TRUE on an empty path.

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As documented. 😉

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I guess that answers that. 

[Darren]

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for(imstuck) wrote:

I guess that answers that. 

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Now, whether or not an empty path *should* refer to the mounted drives of the system is certainly a valid question. But currently, that's how all the File I/O functions and VIs treat an empty path.

[GregFreeman]

I can say from my experience today, it's counter intuitive. But maybe it's not for someone with more of a computing background. I guess the fact that it's documented is fine, but it certainly could bite someone whether it's mentioned in the help or not. My initial thought when I saw this behavior wasn't to go look in the help.

[JÞB]

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@for(imstuck) wrote:

I can say from my experience today, it's counter intuitive. But maybe it's not for someone with more of a computing background. I guess the fact that it's documented is fine, but it certainly could bite someone whether it's mentioned in the help or not. My initial thought when I saw this behavior wasn't to go look in the help.

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Now you understand a basic flaw in your thought process.  Next time.....

Looking in the help file is not evil. (I may need to change my signature line)

That doesn't make it a poor u-nugget though!  Some of the best have been straight out of the help file.

[Yamaeda]

List folder with an empty path gives the mounted drives, so the empty path the base of the file system. That's how i imagine it. 🙂

/Y

[JB]

Thanks to this 6 1/2 years old post, I have never been bitten.

Thank you Darren. You didn't loose your time!

[GregFreeman]

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@JB wrote:

Thanks to this 6 1/2 years old post, I have never been bitten.

Thank you Darren. You didn't loose your time!

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Doh, the response in that thread about the windows function is from my coworker 

[PaulG.]

Basic programming minutiae that may bite you some day: If you're going to change the basic functionality of someone else's code, at the very least make the changes to a copy, change the icon and give the copy a new name. I was recently bitten by a vendor-provided driver that had major modifications done to it here in-house and was not documented. Just changed. That was years ago. I inherit a new project and need these drivers. When the code didn't work as expected I first assumed I was doing something wrong. "Why would the vendor code create a problem? It's worked well for years."..."What do you mean ReadValue.vi is not the same as ReadValue.vi?" 

[nathand]

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@JÞB wrote:

On a related note:

I'm pretty sure I looked through the help.... I did not find a suitable explaination for this Right Click option ....

It seems like minutia that will bite visciously if angered.

Has anyone trained this dog to do tricks?

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Were you actually looking for an explanation of this? Let's say you wire a 12-element array of booleans, with the output configured as 16 bits (because it needs to be a whole number of bytes). The data will be in the low 12 bits. What should the upper 4 bits contain? If the sign extension mode is "Never" then those upper 4 bits are 0. If the Sign Extension Mode is Always, then the upper 4 bits are set to the same value as the last element of the array. If Sign Extension Mode is "If Output is Signed" then it will act like "Never" when the output configuration is unsigned, and "Always" when the output configuration is signed.