I am working on a C project I downloaded from the Internet, and I need to use some PLplot functions for visualization.
However, I am quite new to both PLplot and cmake, and I need help to modify the CMakeLists.txt file accordingly.
I tried adding the following in the CMakeLists.txt file, but it didn't work (failed to find PLplot):
PKG_CHECK_MODULES(PLPLOT REQUIRED plplot)
INCLUDE_DIRECTORIES(${PLPLOT_INCLUDE_DIRS})
LINK_DIRECTORIES(${PLPLOT_LIBRARY_DIRS})
ADD_EXECUTABLE(main main.c)
TARGET_LINK_LIBRARIES(main ${PLPLOT_LIBRARIES})
I also tried to define the paths manually as follows:
SET(PLPLOT_INCLUDE_DIRS "/usr/local/PLplot/include/plplot")
SET(PLPLOT_LIBRARY_DIRS "/usr/local/PLplot/lib")
but it is still failing, I guess because I didn't define PLPLOT_LIBRARIES which I don't know what it is
Note that on the laptop I am working on (running Kubuntu OS), PLplot is installed under /usr/local/PLplot
Related
I have recently started programming on Clion, and I would like to create a Snake game in C language. I have downloaded all the necessary SDL libraries via Homebrew, and I have copied these files into my Developer/CommandLineTools/usr/ folder. My C compiler is in this folder.
I have tried using CMakeLists.txt but I cannot get it to work properly.
cmake_minimum_required(VERSION 3.17)
project(test)
set(CMAKE_C_STANDARD 99)
INCLUDE(FindPkgConfig)
pkg_check_modules(SDL2 REQUIRED sdl2)
pkg_check_modules(SDL2_IMG REQUIRED sdl2_image)
pkg_check_modules(SDL2_TTF REQUIRED sdl2_ttf)
pkg_check_modules(SDL2_MIXER REQUIRED sdl2_mixer)
find_package(SDL2 REQUIRED)
find_package(SDL2_IMG REQUIRED)
find_package(SDL2_TTF REQUIRED)
find_package(SDL2_MIXER REQUIRED)
add_executable(test ${PROJECT_SOURCE_DIR}/src/main.c)
include_directories(${PROJECT_SOURCE_DIR}/assets)
include_directories(${SDL2_INCLUDE_DIRS}
${SDL2_IMG_INCLUDE_DIRS}
${SDL2_TTF_INCLUDE_DIRS}
${SDL2_MIXER_INCLUDE_DIRS})
link_directories(${SDL2_LIBRARY_DIRS}
${SDL2_IMG_LIBRARY_DIRS}
${SDL2_TTF_LIBRARY_DIRS}
${SDL2_MIXER_LIBRARY_DIRS})
target_link_libraries (test
${SDL2_LIBRARIES}
${SDL2_IMG_LIBRARIES}
${SDL2_TTF_LIBRARIES}
${SDL2_MIXER_LIBRARIES})
I have looked through many similar questions here on stackoverflow but none of them seemed to solve my issue.
If I include the find_package, I get this error message:
Could not find a package configuration file SDL2_IMG and so on. If I leave it out I get this library not found for -lSDL2_image.
sdl2 libraries should download individually. mixer, ttf, etc
I worked with SDL2 on XCode without problem (easy)
Rather then compiler location, I prefer project location.
By the way, I indicate header files as path
I wish these help you.
I've been programming C for a while with Visual Studio, but now switched to CLion. My programming and target system is Windows10.
Within Visual Studio, I was able to include the required DLLs like "vcruntime140d.dll" and "ucrtbased.dll" inside my exe.
I did this by going into the project settings and set configuration settings - C/C++ - code generation - runtime library to "Multithreaded-Debug (/MTd)".
Doing this I was able to run the resulting exe without having errors like "vcruntime140d.dll is missing" or "ucrtbased.dll is missing".
But how can I achieve this within CLion?
I've been searching for a while now, and I found a lot of tutorials on how to include .lib files but not for DLLs (I don't have the code for).
With Clion, you actually are working with CMake. So the question is to be like how to link dlls within CMake.
There are many ways to do. e.g.
link_libraries
target_link_libraries
If the library could not be found by default, use find_library to search for it.
If these functions seems too strange to you, check this tutorial from the CLion team.
Update
As in the comment you asked, your problem is how to load a dll without lib. To address this, you could dynamicly load the dll, or make a lib from the dll.
For Windows multicopies problem, add following into your CMakeLists.txt
foreach (flag_var
CMAKE_C_LINK_FLAGS
CMAKE_C_LINK_FLAGS_DEBUG
CMAKE_C_LINK_FLAGS_RELEASE
CMAKE_CXX_LINK_FLAGS
CMAKE_CXX_LINK_FLAGS_DEBUG
CMAKE_CXX_LINK_FLAGS_RELEASE
CMAKE_EXE_LINKER_FLAGS
CMAKE_EXE_LINKER_FLAGS_DEBUG
CMAKE_EXE_LINKER_FLAGS_RELEASE
CMAKE_C_FLAGS
CMAKE_C_FLAGS_DEBUG
CMAKE_C_FLAGS_RELEASE
CMAKE_C_FLAGS_MINSIZEREL
CMAKE_C_FLAGS_RELWITHDEBINFO
CMAKE_CXX_FLAGS
CMAKE_CXX_FLAGS_DEBUG
CMAKE_CXX_FLAGS_RELEASE
CMAKE_CXX_FLAGS_MINSIZEREL
CMAKE_CXX_FLAGS_RELWITHDEBINFO)
string(REPLACE "/MD" "-MT" ${flag_var} "${${flag_var}}")
endforeach ()
I am a relatively inexperienced C developer with no previous experience in integrating libraries made by other developers into existing projects.
Basically, I need a means of parsing JSON data in an AVR microcontroller for a university project. To this end I attempted to download and integrate jansson (https://github.com/akheron/jansson) into my existing build of the microcontroller code. I am working with Atmel Studio in Windows 10, but I have also installed Code::Blocks with MinGW GCC (on the same Windows 10 installation) for the purpose of building the library, and to attempt to integrate the library into a native Windows application. So far, neither has been successful, and I get the same errors. All of the online resources I've found so far have been to basic to be useful, or well beyond my comprehension.
This is what I have done thus far:
I began by attempting to build the software and then integrate it into an existing project per the instructions in https://jansson.readthedocs.io/en/2.11/gettingstarted.html. I installed CMake, built the project files for Code::Blocks with cmake.exe -G “CodeBlocks - MinGW Makefiles”, then opened the project and built everything. A few of the targets (I believe related to testing) failed to build, but jansson itself built and output libjansson.a to the \lib\ directory, so I didn’t think too much of it.
That is as far as I’ve been able to get. In both Atmel Studio and Code::Blocks, I do the same thing: add jansson.h to the relevant include paths, add #include “jansson.h” to all of the relevant files, and add libjansson.a as a library in each IDE’s respective linker options. I’ve tried various things like adding and removing flags to the linker, but the output is always “cannot find -ljansson”, “undefined reference to ‘json_object_seed’” (which is a function in the API I’m calling for no reason other than to see if the project has built properly) and/or “ld returned 1 exit status”.
I cannot help but feel as if the issue is with the line “cc -o prog prog.c -ljansson” in the documentation linked above. I really just don’t understand how to set up the linker properly to get the project to build.
If anyone could give some insight into what I’m doing wrong/the correct way to link this library I would appreciate it a lot.
The library itself should be built with appropriate toolchain. I assume that you built your library twice, one version using MinGW toolchain and other with avr-gcc toolchain.
If you compile target application and linker cannot find library, then try to add path of directory that contains *.a file of library to linker settings (linker search path). Let's say you have: /path/to/lib/libjansson.a
In Code::Blocks: Project → Build options → Search directories → Linker add /path/to/lib/. Then it should link with include path set, for example: cc -o prog prog.c -ljansson -L/path/to/lib/
In Atmel Studio when you add a library in Solution Explorer → Libraries → Add Library it should automatically add library search path to linker options. If you check Project → Properties → AVR/GNU Linker there should be (between other options): -Wl,-ljansson -Wl,-L"/path/to/lib/"
If you copied library files (libjansson.a and jansson.h) to your application's project directory, it will be convenient to use relative paths to library files.
The title states the problem statement: I'm trying to create a CMake project utilizing the libwebsocket library, but I can't find any information for doing so.
Is there anyone who have tried this? A simple CMakeLists.txt for e.g. the test-server program would be much appreciated!
I've compiled and installed the library on my Ubuntu 14.04 machine.
EDIT: I would also like to know if anyone has experience in using the libwebsocket lib w/ C++?
EDIT 2:
After using #evadeflow's answer I'm able to run cmake and build the project. However now I get the following runtime error:
And here's an ls of the /usr/local/lib/ folder
It seems like the libwebsockets.so.7 file is not found?
From CMake:
${LIB_WEBSOCKETS_INCLUDE_DIRS} = /usr/local/lib
${LIB_WEBSOCKETS_INSTALL_DIR} = /usr/local
EDIT 3:
Solved edit 2 by:
Editing the file /etc/ld.so.conf and add /usr/local/lib.
Reference: https://lonesysadmin.net/2013/02/22/error-while-loading-shared-libraries-cannot-open-shared-object-file/
If you've already installed libwebsockets, something like this ought to work:
cmake_minimum_required(VERSION 2.8)
find_package(PkgConfig)
pkg_check_modules(LIB_WEBSOCKETS REQUIRED libwebsockets)
get_filename_component(
LIB_WEBSOCKETS_INSTALL_DIR
${LIB_WEBSOCKETS_LIBRARY_DIRS}
DIRECTORY
)
add_executable(
test-server
test-server/test-server.c
test-server/test-server-http.c
test-server/test-server-dumb-increment.c
test-server/test-server-mirror.c
test-server/test-server-status.c
test-server/test-server-echogen.c
)
target_link_libraries(
test-server
${LIB_WEBSOCKETS_LIBRARIES}
)
set_target_properties(
test-server
PROPERTIES
INCLUDE_DIRECTORIES
${LIB_WEBSOCKETS_INCLUDE_DIRS}
LINK_FLAGS
"-L${LIB_WEBSOCKETS_LIBRARY_DIRS}"
COMPILE_DEFINITIONS
INSTALL_DATADIR="${LIB_WEBSOCKETS_INSTALL_DIR}/share"
)
This is basically a stripped-down version of what's in the CMakeLists.txt file from the libwebsockets github project, without all the platform- and build-specific conditionals.
I hope this is enough to satisfy your request for a 'simple' CMakeLists.txt example. I tested it with CMake version 2.8.12.2; it should work fine as-is if you've installed libwebsockets to its default prefix of /usr/local; however, if you installed to a different location, you will need to set PKG_CONFIG_PATH in the environment from which you invoke cmake.
Also, as explained in the CMake documentation, you will need to replace DIRECTORY with PATH in the get_filename_component() invocation if you're using CMake 2.8.11 or earlier.
UPDATE: Regarding the file not found error from your follow-up comment, this is almost certainly due to libwebsocket.so[.7] not being on the linker's default path. There are at least three ways to fix this, but the easiest way to verify that this is the problem would be to just launch the app from the terminal using:
$ LD_LIBRARY_PATH=/usr/local/lib ./test-server
If it works, you know that was the issue. (Oops—I see you've figured it out in the meantime. Yeah, updating /etc/ld.so.conf is another way. Or, you can force CMake to link to the static version of libwebsockets [as described in this answer] is another. But I like your solution best.)
UPDATE: One thing that wasn't mentioned about /etc/ld.so.conf is that you generally need to run sudo /sbin/ldconfig after editing it in order to update the shared library cache. And—when setting non-default paths for a particular application—many people consider it good form to add a new 'sub-config file' in /etc/ld.so.conf.d rather than edit the global ldconfig file. (For the case of adding /usr/local/lib, though, this is such a common requirement I'd be inclined to dump it in the global config, which is what lots of Linux distros do, anyway.)
Sorry for a question that might appear stupid to more experienced developers: I am still a newcomer to C and C++.
I come from Python/Java development land and am trying to get a better insight into C and C++. I installed JetBrains CLion and cloned CPython mercurial repository. However when I started looking at the source code, I realized that Clion was highlighting a lot of constructs that seemed to be working. For instance:
Or
As far as I can see, Clion seems the have problem with the identation style of Python, C code, but once again, I might be wrong.
How Clion configurations can be altered for it to properly parse the CPython code?
CPython uses GNU Autotools for the build, but that toolset is not supported by CLion. See issues CPP-494 and CPP-193. CLion currently supports only one build system - CMake.
You can create your own CMakeLists.txt file and list the sources in there. This will help CLion to understand the structure of the source tree and allow it to find the headers etc:
cmake_minimum_required(VERSION 3.0)
project(cpython)
file(GLOB SOURCE_FILES
Python/*.c
Parser/*.c
Objects/*.c
Modules/*.c)
include_directories(Include)
add_executable(cpython ${SOURCE_FILES})
For the actual build, use standard build tools from command line. Alternatively, custom command can be added to CMakeLists.txt to call make. See add_custom_command for that.
As mentioned in the above answer you need a CMake Project to allow CLion to build Python.
In fact there is already a CMakeList.txt-files for CPython, that is maintained independently from the official sources:
https://github.com/python-cmake-buildsystem/python-cmake-buildsystem
I didn't test it with CLion but it should do the job...