How to install Boost library? How to add library to project?

mzimmers · 26 Dec 2022, 17:12

No, something's still wrong with your .pro file. ~~You need to get rid of that entry for the BoostLinkingTest.pro file.~~

EDIT:
disregard that last line.

May I see the complete contents of your .pro file?

aret777 · wrote on 26 Dec 2022, 17:12

@mzimmers Its same from the beggining. I created now new project just for test, but same errors:

mzimmers · 26 Dec 2022, 17:25

My bad...I gave you bad advice on the LIBS entry. You need to specify the full path to the library you want to use. There may be a way to wildcard that; I'll do some looking. In the meantime, if you know specifically which boost libraries you need, modify your LIBS entry to contain the full path to those libraries.

EDIT:

Look at the LIBS entry on this page for how to explicitly add libraries to your project.

aret777 · wrote on 26 Dec 2022, 17:25

@mzimmers Okay, if it will work, its fine.
But what file I need then to add to LIBS?

LIBS += /home/user/Documents/BoostLibrary/stage/lib/libboost_program_options.a
LIBS += /home/user/Documents/BoostLibrary/stage/lib/libboost_program_options.so
LIBS += /home/user/Documents/BoostLibrary/stage/lib/libboost_program_options.so.1.81.0
And, how to link 2 libraries? Just to repeat LIBS+= "path" again?

And just for curiosity - I am doing tutorial with that boost library, it says:

Remember that the Boost.ProgramOptions library consists of more than just header files, so
Therefore, your program must link with the libboost_program_options library.
We did linkage?

mzimmers · 26 Dec 2022, 17:48

You should only need one of those libraries. I'm working from memory, so you might want to double-check me, but an .so library is a dynamic library, while a .a is a static library. The one with a specific version number appears to be the actual library, while libboost_program_options.so is a link (so when you update boost, you don't have to rebuild your project. I'd use the link in your LIBS statement.

When you want to add multiple libraries, you can either have multiple LIBS statements (just remember to use "+=" or the second LIBS statement will undo the first), or you can concatenate the needed libs in one LIBS statement.

aret777 · wrote on 26 Dec 2022, 17:48

@mzimmers Thanks a lot.
But now I get other error:

I tried to google, found this:
https://stackoverflow.com/questions/36090824/trouble-using-boost-cannot-open-shared-object-file
https://forum.qt.io/topic/58963/error-while-loading-shared-libraries-cannot-open-shared-object-file-no-such-file-or-directory/3

but adding this flags from solutions doesnt work... (however, advices are very old, more than 6 years passed...)

mzimmers · wrote on 26 Dec 2022, 18:00

Interesting. We're getting away from my area of expertise -- it's been awhile since I've developed for Linux -- so I'm not sure how much help I'll be.

Looking at the link you provided...I wonder if you need to use this variable. I don't remember having to use it back when I did use Qt for Linux, but who knows.

Maybe someone more knowledgable than I can chime in here.

SGaist · 26 Dec 2022, 20:30

Hi,

You can define the LD_LIBRARY_PATH environment variable in the Run part of the project panel and point it to where your boost libraries are.

One question though: why not use the boost libraries from your Linux distribution ?

aret777 · S SGaist 26 Dec 2022, 19:38

@SGaist And what I need to do here?

One question though: why not use the boost libraries from your Linux distribution ?
Because I am newbie, obviuos steps when you need a library - download it from library site.
If it will be easier to use them from Linux and link them to projects in Qt - awesome!

SGaist · wrote on 26 Dec 2022, 21:02

See the environment block ? That's what you need to change.

aret777 · wrote on 27 Dec 2022, 13:03

Humm, I already have this variable and it doesnt permit set another one (LD_LIBRARY_PATH)
I tried to set variable in analogue with others... but it changed nothing in compiler errors.

SGaist · 27 Dec 2022, 19:20

The error you show is a run time error not a compiler error.

Where exactly is that library located ?

mzimmers · 27 Dec 2022, 19:25

@SGaist according to the console read-out in the first post, it appears that library is located at: /home/user/Documents/BoostLibrary/stage/lib, which is indeed part of the definition of LD_LIBRARY_PATH.

SGaist · 27 Dec 2022, 19:27

@mzimmers good point, I have misread that part.

Second thing I would do is run ldd to see what it has to say and the first would be to switch to the distribution provided boost if recent enough.

mzimmers · S SGaist 27 Dec 2022, 19:25

@SGaist agreed, but (IMO) it's still worth knowing why this isn't working for him. At this point, it seems like he's done everything necessary.

BTW: when did Linux distros begin including Boost?

SGaist · wrote on 27 Dec 2022, 19:31

The exact debut, I don't know but at least Debian does.

aret777 · 28 Dec 2022, 15:21

Okay, here is the my ldd commands - I dont know why it wont work

Anyway, I can deinstall Boost if needed. I downloaded from Boost site the «boost_1_81_0.tar.gz» archive, it still on my download folder.

mzimmers · 28 Dec 2022, 15:32

@aret777 I believe you want to run ldd on your executable, to see what dependencies it has. You appear to be running it in the boost directories.

aret777 · 28 Dec 2022, 16:23

@mzimmers what executable? Of a QT project? It doesnt build.

mzimmers · wrote on 28 Dec 2022, 16:23

@aret777 yes it does build - that's what SGaist was trying to tell you. If you look in your build directory, under debug or release or whatever build mode you're using, you should find an executable. Run ldd on that file.