how to link with "so" files

nishiokas

We developing an Qt-application.(boot2qt 5.9.1)
It link with "libaaa.so" file.

In this case is ok that so-file is in "(root)lib/" folder.
The Qt-application can like with the so-file.

However, in other case isn't ok that so-file is in "home/root/abc/lib"
folder.
Of cause I could set "home/root/abc/lib" in "LD_LIBRARY_PATH"
or "PATH".
But when I compile in this situation, I can see this message on Qt-Creator-
Output
: error while loading shared libraries: libthincapayment.so: cannot open
shared object file: No such file or directory

How can I use so-file without "(root)lib/" folder?
Thanks.

jsulm

@nishiokas You need to specify the path where linker should look for the library using -L parameter.
See https://doc.qt.io/qt-5/qmake-variable-reference.html#libs
Or are you talking about running your app?

nishiokas

Thanks for your reply!

Or are you talking about running your app?

Yes.

I wrote it ".pro" file and compile is okey.

LIBS += -lz
LIBS += -L"abc/lib" -labc
LIBS += -L"/home/root/abc/lib" -labc

But when the app start, it doesn't work.

Thanks.

jsulm

@nishiokas So, then it has nothing to do with building.
This is a runtime issue. If you put the lib into a folder which is not searched for libraries by the system then you have to set LD_LIBRARY_PATH before starting the app (not before building it!) or put the lib next to the exe (in same folder).

JKSH

@jsulm said in how to link with "so" files:

put the lib next to the exe (in same folder)

This works for Windows but not Linux.

For Linux, you'd need to use chrpath or patchelf to set your application's RUNPATH (or RPATH) to $ORIGIN if you want it to search its folder for libraries.