Compiling mex file that depends on external libraries with extension .so.n

I have written a file myprog.cpp and is to be compiled in MATLAB. The program has external library dependencies libnewfile1.so and libnewfile2.so.3. I compiled using following instruction from MATLAB command window.

mex myprog.cpp -lnewfile1.so -lnewfile2.so.3 -L"path to library folder"

I get he following error while compiling.

Error using mex

/usr/bin/ld: cannot find -lnewfile1

/usr/bin/ld: cannot find -lnewfile2.so.3

collect2: error: ld returned 1 exit status

Could anyone please tell me how to compile a cpp file that has external library dependencies?

Later I tried adding the path to LD_LIBRARY_PATH using setenv and getenv shows the above path in LD_LIBRARY_PATH. But still I get the same error.

[Adam]

Shouldn't you be using

-llibnewfile1.so -llibnewfile2.so

? It is a while since I have linked a mex against external libraries, though my case dlls, but you need to put the full name of the library file I am fairly sure.

[Michael Mathew]

No I still get the error:

Error using mex

/usr/bin/ld: cannot find -llibnewfile1.so

/usr/bin/ld: cannot find -llibnewfile2.so.3

collect2: error: ld returned 1 exit status

[Michael Mathew]

I did solve it. The problem was Matlab does not recognise libraries with extensions other than .so; Hence I renamed the library to .so and that solved the issue.

Answer 1

[Albert Hofkamp]

Bit late to the party, but the answer is that -l adds a "lib" prefix and a ".so" suffix to its argument, so linking with -Lpath/to/library/dir -lnewfile1 -lnewfile2 will do the trick.

Note that Matlab may add requirements to library-files such as position-independent code, which may or may not have been used while compiling the library.