LLB's Useful or Useless

[DredPirate]

I was told by an old time LV programer that LLBs were created because of the filename length and character restrictions in DOS. When microsoft increased the filename length, LLBs became useless but were still very popular so NI continued there support.

In my past jobs the use of LLBs was looked upon as worse than using globals. Now at my current company LLBs are used exclusively by every LV programmer but me.

Am I missing some special features of LLBs.

From what I've seen its easier to use Save with Options-Development Distribution-To New Location_ Single Prompt_Preserve Hierarchy to extract the VIs into one folder. Then Zip them for distribtion. (BTW: I think LV 8 will include some sort of Zip functionality.)

I hate the fact that LLBs strip the hierarchy. It makes that much harder to debug and modify someone elses code because you have to search through a huge list of Vis to find anything instead of having a useful and desciptive folder hierarchy.

Maybe I'm missing something because they still seem to be popular in the LV community.

[Michael Aivaliotis]

I like your avatar. What did they call those things? curiously large rodents? Don't remember but it was funny. One of my many favorite movies.

Getting to the LLB stuff now. I would say ditch them... However it seems like your employer is stuck in the stone ages for some reason. I'm curious, do they use source code control? I bet not. Otherwise they would not be using LLB's. How can you do source code control on individual files when they're wrapped in an LLB.

Don't forget the dangers of LLB corruption! This is the biggest gotcha in LLB's. When VI's are saved into LLB's the file must be kept open and if there is a glitch during the save, the entire LLB is toast. There go all your VI's. NI support can fix this but who needs the hassle?

He's not dead, just mostly dead...

[Khalid]

National Instruments recommends that you save VIs as individual files,

organized in directories, especially if multiple developers are working on

the same project.

LabVIEW 7.x User Manual, Page 7-12.

If you're stuck with LLBs in an ongoing project, here's a trick you can use: in your file structure, create a folder (directory) to represent the LLB -- name it exactly the same as the LLB, for instance, "myLibrary.llb" including the 'dot llb' part. And then put the VIs from the original LLB under this folder. (You may use the Library Manager to do this... )

This way, you are now working with individual VIs (great for source-code control, etc.), and at the same time your rest of the system isn't broken because the paths to these VIs are still the same as before.

-Khalid

[DredPirate]

Great trick. I've been ripping apart alot of LLBs lately. I can't believe how popular they still are.

BTW Mike, thanks and they were ROUS's (Rodents Of Unusual Size).

And thanks for the info. Just more ammo for the argument to kill LLBs.

[Rolf Kalbermatter]

I hate the fact that LLBs strip the hierarchy. It makes that much harder to debug and modify someone elses code because you have to search through a huge list of Vis to find anything instead of having a useful and desciptive folder hierarchy.

Maybe I'm missing something because they still seem to be popular in the LV community.

You summed up most of the negative sides of LLBs and got the rest of them in the other posts. I think using LLBs nowadays during development is a big no-no. I do use them sometimes for distribution of function libraries AFTER the development is finished and I wouldn't expect many changes anymore. Still this is only for distribution. The actual source code for further development or bug fixing is always kept in a directory instead and archived as such.

Rolf Kalbermatter

[wrath_of_con]

With all this LLB info and Princess Bride talk, I want to use some creative license with a movie quote and say,

Haha.. you fool! You fell victim to one of the classic blunders. The most famous is: Never get involved in a land war in Asia. Only slightly less well known is this: Never get involved with LLBs when a project is on the line!

[Yair]

One of my many favorite movies.

Mike, if you liked the movie, you absolutely have to read the book. It has a whole darker and much funnier aspect which has been completely cut out in the movie adaptation (which shouldn't have been too hard, as you will understand when you read the book). William Goldman, who wrote this, as well as "Butch Kassidy and the Sundance Kid", definitely has a sense of humor. One word of warning, though - do not let your children read this book. If you do, that's at your own risk.

Incidentally, if memory serves, the name is actually Dread Pirate Roberts, but it doesn't look like the invision board gives you the option to change your user name.

And if you people like pirates, you should play the Monkey Island games.

As for LLBs, one thing I do use them for is polymorphic utility VIs. Since I have backup for those VIs, I don't really mind corruption, and they're easier to organize.