i downloaded mlpack and its dependencies from ubuntu repos as described in the docs using :
sudo apt-get install libmlpack-dev libmlpack-bin and then i ran :
pkg-config --cflags mlpack
And pkg-config --libs mlpack
And pkg-config --modversion mlpack
to make sure everything works and i got the expected outputs. Now in codeblocks i put the mlpack library directory in the search directory and the pkg-config --cflags mlpack in the compiler options, and the pkg-config --libs mlpack in the linker options. But when i build it gives me ld errors: libraries were not found. What frustrates me is that i have done the exact same procedure with other C++ libraries like OpenCV and it worked. So any help ? Does anyone managed to get it work before on linux ?
------Update------
I managed to fix it by only adding -lmlpack and -larmadillo to the linker options and not adding all --libs.
Related
I am new to the Point Cloud Library. There is a thing that has been bugging me for some time.
So, on my system, whenever I have to compile a C++ program, which requires OpenCV libraries to be linked, I use the following terminal command:
g++ -std=c++11 fileName.cpp -o executableFile `pkg-config --cflags --libs opencv`
Now, things have turned to a point where I have to use PCL. But, everywhere (including the PCL's official website) people link PCL libraries using a CMake file, and I am not familiar with CMake.
Is there a way to include the PCL libraries without writing a CMake file and just including some more flags/parameters to the terminal command?
I am using Ubuntu 18.04.
I experimented for a while, and here is how I figured this out.
man pkg-config tells you the folders where pkg-config looks for .pc files. So, I checked those folders for the exact .pc file names that I want pkg-config to link with my .cpp file. I found the required file (pcl_io-1.11.pc) at \usr\local\lib\pkgconfig
Next, I modified my terminal command to the following (please consider two back-quotes as a single back-quote below)
g++ -std=c++14 pcd_write.cpp -o pcd_write ``pkg-config --cflags --libs pcl_io-1.11`` -lboost_system
Note: Not including the -lboost_system would result in another error message. I found this helpful.
This compiled successfully. But, on running the executable, I would get this error message:
./pcd_write:error while loading shared libraries:libpcl_io.so.1.11:cannot open shared object file:No such file or directory
The solution to this problem was found here
sudo /sbin/ldconfig -v
Then, running the executable gave the expected results.
I have installed "libsdl1.2-dev" and "libvlc" (with sudo apt-get install blah) in Raspbian on my Raspberry Pi, I'm using gcc to compile the example project from https://wiki.videolan.org/LibVLC_SampleCode_SDL/
This is my compile command:
gcc -fpermissive test.cpp -lvlc -lsdl1.2-dev -o test
It seems to compile (after I added -fpermissive and manually placed the vlc headers in usr/include/vlc) the error seems to happen during the linking phase, I get these 2 errors;
/usr/bin/ld: cannot find -lvlc
/usr/bin/ld: cannot find -lsdl1.2-dev
I'm a bit new to Linux and I can't work out why it can't find them. I'm also unsure where it installs them by default, there seem to be a few different places they could be.
Use pkg-config to get the needed compile and link flags. pkg-config --cflags sdl libvlc will print the needed compilation flags, and pkg-config --libs sdl libvlc the needed link flags. You can use the $() feature of the shell to embed the output of pkg-config directly into your compile command. Also, use g++ to compile and link C++ code. gcc is for C code.
g++ $(pkg-config --cflags sdl libvlc) -fpermissive test.cpp -o test $(pkg-config --libs sdl libvlc)
The package names sdl and libvlc correspond to *.pc files that are installed in /usr/lib/pkgconfig. If no such files exist, then that means you forgot to install the -dev versions of the sdl and vlc libraries. So check if there's a libvlc-dev package you need to install. Use this:
apt-cache search vlc | grep dev
See if there's a dev package for libvlc that you need.
To install libraries and header files, try sudo apt-get install libvlc-dev this should install all the dependent libraries in the correct library paths. sudo apt-get install vlc is used to install the application which in your case you dont need.
Try sudo apt-get install vlc, you're probably missing some plugins and stuff
I have been working on a program in SDL and I would like to send it to my friends who only run a Windows environment. I have done some reading and found that I should use mingw to cross-compile for Windows. The binary I found and compiled was x86_64-w64-mingw32-g++, however I am getting some issues getting my program to compile. Using the following command I get the following error:
/usr/bin/x86_64-w64-mingw32-g++ sapphire.cpp `pkg-config --cflags --libs sdl2` -lSDL2_image -lSDL2_mixer -lSDL2_ttf -std=c++11
fatal error: iconv.h: No such file or directory
While I realize I should make a makefile eventually, I am not going to do that now.
I tried installing iconv (Version 1.15) from here and used the following commands to compile it:
./configure --prefix=/usr/local
make
make all
My iconv.h is located in /usr/include but if I include that I get another error for missing gnu/stubs.h and if I include that then I get a myriad of errors that I'm not sure how/if I could fix seen here. Does anyone know how I could perhaps fix this? I would appreciate any help!
Thanks in advance!
You can use pkg-config with mingw in a crosscompiler environment but you should take care to where pkg-config searches for his .pc files.
I'm assuming your mingw crosscompiler is installed in /usr/x86_64-w64-mingw32, change it to the installation path where his "include" and "lib" subdirectories are.
Provided SDL windows developement package is installed in the same prefix on your computer and the installation has a correct pkg-config .pc file you can do:
export PKG_CONFIG_PATH=/usr/x86_64-w64-mingw32/lib/pkgconfig
and then try pkg-config from the command line:
pkg-config sdl2 --cflags
This should point you to some path inside /usr/x86_64-w64-mingw32, if it does your compilation will be successful.
Please note that if you want to compile a package for crosscompile (like the iconv you tried to compile) you should add to the ./configure script parameters:
--host=x86_64-w64-mingw32 --prefix=/usr/xx86_64-w64-mingw32
... and this may work or not, depending the package support the mingw32 compiler or not.
The way you compiled iconv built another linux version of it in /usr/local!
NOTE: As far as I know Ubuntu does not provide a windows package for SDL2, while other linux distro do, so you'll need to cross-compile SDL2 with the option I gave before you can compile your code. SDL2 does support cross-compilation using mingw.
According to this answer I would have to checkout entire repo of tesseract.
How do I install minimal packages of tesseract with c++ APIs for development and English language detection in linux (ubuntu)?
Update - Reason for using the large SVN repo is to enable g++ compilation.
When installed with apt-get:
bhp#Virtual-Machine:~/Desktop/bhp/opencv-tesseract$ pkg-config --cflags --libs tesseract
Package tesseract was not found in the pkg-config search path.
Perhaps you should add the directory containing `tesseract.pc'
to the PKG_CONFIG_PATH environment variable
No package 'tesseract' found
When built with source:
bhp#Virtual-Machine:~/Desktop/soft/tesseract-ocr$ pkg-config --cflags --libs tesseract
-I/usr/local/include/tesseract -L/usr/local/lib -ltesseract
In trying to get Allegro (A C++ game programming library) to work with a very simple C++ application in Ubuntu 12.04, I am unable to get the program to compile with the allegro header definitions. It returns the error allegro.h - no such file or directory found. I tried running a pkg-config to find the proper linker command, but that didn't help in compilation.
I am almost certain it is installed correctly at this point. I tried using a pkg-config --cflags --libs allegro-5.0 for the include file paths, none of which worked when using in the g++ compile line.
Thanks in advance.
Running a pkg-config --cflags --libs allegro-5.0 told me wrong on the include path. It told me to use -I/usr/local/include and after some digging into that folder, I found that the include path is -I/usr/local/include/allegro5 instead. It is compiling fine now.