I wrote a program that reads a GeoTiff file with GDAL. To compile it, I write:
g++ my_program.cpp -lgdal
However, I want to run this code with Clion. How do I add this -lgdal to the CMake file?
The -l is an indication to the linker to link the gdal library to your executable, so the corresponding CMake command is target_link_libraries(). So your CMake might look something like this:
add_executable(MyExecutable my_program.cpp)
target_link_libraries(MyExecutable PRIVATE gdal)
Related
I'm trying to generate a mex function usigin external libraries. I'm using Ubuntu 18 and Matlab R2021a.
In particular I want to compile my file.cpp that uses my cpp library called model.
What I did is
mex -I<path_library_include> -L<path_library_so_file> -lmodel.so -lboost_system -lstdc++ file.cpp -v
where in -I i put the path where is the include of the library in -L the path in which the libmodel.so is located, then I added 2 more libraries and at the end the source file that I want to compile.
In this way I can compile my source but when I try to execute the mex function I get:
libmodel.so: cannot open shared object file: No such file or directory
I also tested the library outside matlab and works fine, this is the command that I use to compile the library outside Matlab
gcc -Wall -I<path_library_include> -L<path_library_so_file> main.cpp -lmodel -lboost_system -lstdc++ -o main
What could be the problem with Matlab?
Thanks to 273K that gave me the right direction.
The problem was that the LD_LIBRARY_PATH was not configured well in fact running /sbin/ldconfig -v my library was not present. So to add the shared library i created a new file as root in /etc/ld.so.conf.d/ called mylib.conf it is not important the name just the extension. Then I run
sudo ldconfig
after that the library was present in fact running
/sbin/ldconfig -v | grep model
where model is the name of my library. it is possible to see the output.
I'm compiling a c++ program using g++ and i am using two libraries called libsdl2-dev and libsdl2-image-dev
I installed both these libraries in my ubuntu machine with the commands
apt install libsdl2-dev libsdl2-image-dev and when I compile the program everything works fine. Then I copied these libraries from /usr/lib/x86_64-linux-gnu/ to my working dir with the binary file to be able to give this folder to someone else.
The problem comes when the user that hasn't installed these libraries tries to open my program by writing ./main (the binary file). Since he hasn't installed these libraries he would get an error like "can't open shared object: no such file or directory".
This happens because the binary file looks for these libraries in /usr/lib etc...
What i need
I need that my binary file looks for these libraries in the same folder,and not in /usr/lib/x86 etc.., from what I read I have to do something like rpath
The IDE used is Sublime Text and the syntax used to compile all my files is this:
g++ -c src/*.cpp -std=c++14 -m64 -g -Wall -I include && g++ *.o -o bin/debug/main -lSDL2main -lSDL2 -lSDL2_image && ./bin/debug/main`
Structure of folders
I got the project dir with and inside that i got 4 more directories, each one called: bin (with the debug subdirectory, where we got the final compile), include (with hpp files), res (with all textures), and src with all cpp files to compile, the other files are project files and .o files
I'm using Ubuntu 20.04-2 LTS and the same is for the other user's PC
Thanks in advance for any help!
That's because the dynamic linker loading runtime dependencies looks for them in some specified locations, which are "by default" your system library directories (where those libraries got installed by apt).
The other user should ideally install those libraries too (which could be done "automatically" if you build a .deb package with proper dependencies)
Otherwise you would have to change the runpath of your program by adding -Wl,-rpath='$ORIGIN', which makes the dynamic linker look for dependencies just where the binary is located.
$ORIGIN here is a special variable meaning "this executable" which is what you wanted to achieve.
see rpath
and A description of RPATH $ORIGIN
I found a way to resolve!
I used the program patchelf to add an rpath to my directory (linked to the binary file) now everything works
use ldd ./bin/debug/main to check the library
export LD_LIBRARY_PATH =$LD_LIBRARY_PATH:"your library path"
run the program,if this is not work. use patchelf to change the rpath to you r library
So I follow the official tutorial for the installation : https://mongodb.github.io/mongo-cxx-driver/mongocxx-v3/installation/
Neverless, I can't use the produced libraries as static.
So I managed to compile the C version of the driver as described, I've enabled the flag --enable-static=yes with the ./configure before doing make && sudo make install and I got the libmongoc-1.0.a and the libbson-1.0.a which are static. So this far, everything it's alright.
Then I have done the cxx version of the driver, except that there is no configuration file as in the C version. So I've juste done a
cmake -DCMAKE_BUILD_TYPE=Release -DBSONCXX_POLY_USE_BOOST=1 -DCMAKE_INSTALL_PREFIX=/usr/local
from the build folder, followed by a make && sudo make install
So I got the libmongocxx.a and the libbsoncxx.a, but when I try to compile with them, I can't run the binary because I got the following error :
error while loading shared libraries: libmongocxx.so._noabi: cannot open shared object file: No such file or directory
So I understand that is because there is some symbols missing and then I need to use the shared library to run the binary but I don't want this to happend, I want the symbols within the binary that I can run it without any LD_PRELOAD.
Any suggestions ?
I had the same issue in an Ubuntu 16.04 and I run a apt-get update & apt-get upgrade and the problem was solved.
It seems that there were some update to the compiler and some libraries that prevent some test from reaching the shared libraries.
I have a similar question, and solved, now I compiled and run my binary with static libs successfully.
I write my build script using newlisp, but the static link options are very helpful, I paste it here.
c++ /to/your/path/site/code/back_end/builder/object/files1.cc.o ... /to/your/path/site/code/back_end/builder/object/files10.cc.o -o bin/site -static-libgcc -static-libstdc++ -L/usr/lib -lpthread -l:libmongocxx.a -l:libbsoncxx.a -l:libmongoc-1.0.a -l:libbson-1.0.a -lrt -lssl -lcrypto -lsasl2 -l:libboost_log.a -l:libboost_log_setup.a -l:libboost_system.a -l:libboost_thread.a -l:libboost_filesystem.a -lcppcms -lbooster -lcurl -ljsoncpp
I am trying to build and link a C++, cmake-based project with clang (3.0). This project links to several libraries that are installed in a custom directory /my/dir/. This directory is included in the LD_LIBRARY_PATH and LIBRARY_PATH environment variables. Project builds and links fine with g++.
The link command generated and executed by cmake looks like the following:
/usr/bin/clang++ -O3 stuff.cpp.o -o stuff -rdynamic -lmylib
ld then complains with the following message:
/usr/bin/ld: cannot find -lmylib
The link command above runs fine whenever I manually add -L/my/dir/. Is there a way to link without specifying the -L flag?
The $LD_LIBRARY_PATH environment variable (and its various alternatives on other UNIX-based platforms) is used at runtime, not link time, to find libraries.
Using -L is the correct approach and cannot be avoided.
Note: A better approach under Linux (you don't specify your platform so I'm guessing) is to correctly configure a file in /etc/ld.so.conf.d/ and avoid using $LD_LIBRARY_PATH altogether.
I'm using ubuntu 12.03 and trying to use Symbolicc++ library, it is specified in it's README file that the program using this library should be compiled with command g++ -o program program.cpp -lsymbolicc++. I am wondering how can I enter the -lsymbolicc++ pastfix in the cmakelists.txt file and work on kdevelop?
If you already have program added as an executable to cmakelists.txt a'la;
add_executable(program program.cpp)
then you can just add
target_link_libraries(program symbolicc++)
to add that library when linking.