Include libraries into my project folder

问题

I'm programming using C++ and Qt Creator. I need to include the libraries I'm using inside my project folder so that the program can be implemented on any device. What should I do exactly?

I know I should modify the .pro file and I already tried this:

LIBS+=-L"$$_PRO_FILE_PWD_/libs" \
-lvl \

But it does not work. I get this error: error while loading shared libraries: libvl.so: cannot open shared object file: No such file or directory

Any ideas?? Thanks

回答1:

First of all, on Linux qmake generates Makefiles which are used to control your build process. When you add the line

LIBS+=-L"$$_PRO_FILE_PWD_/libs" -lvl

to your .pro file, qmake will see to it that appropriate Makefile target is generated which tells the linker to search for additional libraries in $$_PRO_FILE_PWD_/libs and link to a library libvl.so when linking the executable.

However what you're experiencing is a run-time problem. More specifically, ld-linux.so.2 will try to find and dynamically load shared libraries like libvl.so at runtime. This happens using built-in, such as /usr/lib and user-defined (and/or distribution-defined) paths when the executable is loaded. I refer you to the corresponding man page for ld-linux.so.2 and the man page for ldconfig, which is used to configure user-defined library search paths in a standard way.

When ld-linux.so.2 tries to find libraries, it searches a well defined set of directories (all colon-separated) in the following order:

• if present, the so called DT_RPATH, which can be written into an executable library (deprecated).
• the LD_LIBRARY_PATH (at least for most executables, see the man page for exceptions)
• the DT_RUNPATH which supersedes the DT_RPATH (if any) but delays lookup until after LD_LIBRARY_PATH has been processed. The RPATH and RUNPATH can be used to simulate behavior like on Windows, where the path of the executable is also searched. LD_LIBRARy_PATH, however, is much better suited for this purpose.
• library names present in the cache file /etc/ld.so.cache which is generated by ldconfig using directories specified in /etc/ld.so.conf/ and possibly additional files either directly referred to via inclusion in ld.so.conf or otherwise specified
• the trusted directories, /lib and /usr/lib

If none of the paths mentioned above contain the appropriate shared object, you will get an error that it could not be loaded by ld-linux.so.2.

The solution in your case is simple and come in some variety:

• before executing the program, set the LD_LIBRARY_PATH environment variable using export LD_LIBRARY_PATH={yourSearchPaths}.
• add the LD_LIBRARY_PATH to the invocation of the executable on the command-line, e.g. LD_LIBRARY_PATH={yourSearchPaths} ./{executable}
• provide an executable start-up shell script, e.g. start.sh, which does the above for you and then simply execute the shell-script ./start.sh

来源：https://stackoverflow.com/questions/18977420/include-libraries-into-my-project-folder