I am trying to learn CMake. I have the Mastering CMake book and I'm trying to go through my first "easy" tutorial. Using CMake: Hello World Example
I made it through the first part alright, but when I tried to add the sub folders for the "Building a library" part of the tutorial I'm just not getting it. I followed the instructions all the way to the very end.
**We've seen an example of how to build a program. Now let's make a library as well. The library will be called "namer" and it will have a single function "getWorld" that returns the name of the nearest planet. We choose to put this library in a subdirectory called "namer" - it doesn't really matter where we put it, this is just an example.
I made it a subfolder in my HelloWorld project. Should I be making this a separate project?
**One way we can help CMake find the Namer package (which will be our namer library) is by writing a helper script called FindNamer.cmake. This is just another file written in the CMake language that pokes around in all the places our library might be hiding. Here is an example (put this in "hello/FindNamer.cmake"):
This is my FindNamer.cmake file:
find_path(Namer_INCLUDE_DIRS world.h /usr/include "$ENV{NAMER_ROOT}")
find_library(Namer_LIBRARIES namer /usr/lib "$ENV{NAMER_ROOT}")
set(Namer_FOUND TRUE)
if (NOT Namer_INCLUDE_DIRS)
set(Namer_FOUND FALSE)
endif (NOT Namer_INCLUDE_DIRS)
if (NOT Namer_LIBRARIES)
set(Namer_FOUND FALSE)
endif (NOT Namer_LIBRARIES)
**The important parts here are the "find_path" and "find_library" commands, which look for the header file world.h and the namer library.
I followed the next instructions and at the very end the tutorial includes this:
**If we try again, configuration will still fail since the search path we gave for "find_path" and "find_library" doesn't actually include the needed files. We could copy them, or have added a hard-coded directory to find_path and find_library pointing to where the files are on our hard drive - but better, in the CMake GUI on windows or by running "ccmake ." on Linux, we can just fill in the directories there.
At this point I am completely confused (Newbie!!!!). I don't have a NamerConfig.cmake or namer-config.cmake file and I don't know what the find_path and find_library is supposed to be pointing to.
Thank you in advance for your help,
Severely Confused :-(
I said I was a newbie. I guess I'm a little tired too! Yes, these must be in two separate projects.
Related
I'm a newbie coder and decided on using raylib to learn c / c#.. I saw an example with reasings.h header file and wanted to run that example on my local machine. I installed raylib via https://github.com/raylib-extras/game-premake
Everything worked perfectly and the raylib game runs, however I'm not sure how to use readings.h in the include sections because it says file not found, was curious how I could use this header?
Also I do see the reasings.h in my C drive C:\Users\Hoyos\Desktop\m_c_t\RAYLIB_proj1\raylib-master\examples\shapes.
Any help would be appreciated. ty!
Short answer: Just put the reasings.h in the same folder as your shapes_easings_ball_anim.c file (I suspect you are using this example).
Here you can find a longer answer: Reading the header of a file
I created a simple hierarchial C++ project to help me learn the use of scons as I want to get away from cmake and qmake. I have registered it in a github repository at https://github.com/pleopard777/SConsEx . This project is organized into two primary subdirs; packages contains two libraries and testing contains two apps. The packages dir needs to be built first and when complete the testing dir needs to be built. Under the packages library the core library must be compiled first and the numerics library second. The numerics library depends on the core library. Under the testing dir the core_tests app depends on the core library and the numerics_tests app depends on core and numerics.
I am struggling with what seems to be limited documentation and examples for scons so I am posting this here in search of some guidance. Here are some of the initial problems I am having, any guidance will be greatly appreciated:
1) [Edit/FIXED]
2) In the packages/numerics/ dir the source files depend on the core library. The file numerics_config.h requires the file ../core/core_config.h however when building that core file cannot be found. The following SConstruct lines don't help:
[code]
include = '../../packages'
env = Environment(CPPPATH=include)
[/code]
Again, this is just a start to the project and I am using it to learn scons. Any guidance will be appreciated ... I'm sure I will be asking lots more questions as this project progresses.
Thanks!
P
Fixed in pull request to your repo.
Note you had some c++ issues as well. I've fixed them too.
See:
https://github.com/pleopard777/SConsEx/pull/1
(Please don't delete your repo so others can find the solution as well)
I'm trying out Freeling's API for python. The installation and test were ok, they provide a sample.py file that works perfectly (I've played around a little bit with it and it works).
So I was trying to use it on some other python code I have, in a different folder (I'm kind of guessing this is a path issue), but whenever I import freeling (like it shows on the sample.py):
import freeling
FREELINGDIR = "/usr/local";
DATA = FREELINGDIR+"/share/freeling/";
LANG="es";
freeling.util_init_locale("default");
I get this error:
ModuleNotFoundError: No module named 'freeling'.
The sample.py is located on the ~/Freeling-4.0/APIs/Python/ folder, while my other file is located in ~/project/, I dont know if that can be an issue.
Thank you!
A simple solution is to have a copy of freeling.py in the same directory as your code, since python will look there.
A better solution is to either paste it in one of the locations where it usually checks (like the lib folder in its install directory), or to tell it that the path where your file is should be scanned for a module.
You can check out this question to see how it can be done on Windows. You are basically just setting the PYTHONPATH environment variable, and there will only be minor differences in how to do so for other OSes. This page gives instructions that should work on Linux systems.
I like this answer since it adds the path at runtime in the script itself, doesn't make persistent changes, and is largely independent of the underlying OS (apart from the fact that you need to use the appropriate module path of course).
You need to set PYTHONPATH so python can find the modules if they are not in the same folder.
I realise this is a newb question but I've been racking my brains for hours.
So I want to use the STK (Synthesis Toolkit) to generate sine waves etc. I've downloaded the source files from https://ccrma.stanford.edu/software/stk/download.html
I unzipped the tar.gz using 7zip.
I opened up the demo.cpp project file (under /projects/demo/demo.cpp) and whenever I try to compile it, I receive lots of errors, all starting with "undefined reference to"
I have set the compiler search directory to include the root folder of the stk kit (unzipped as "stk-4.5.0"). My understanding is that I also have to find file for the linker, that is of the type .lib? Is that correct? I haven't been able to find a .lib file to link to.
I feel like this is a simple fix - what am I missing?
You've downloaded a source , not the compiled library which might be used by linker (.lib file) There are three solutions:
1. Compile whole src folder of your download ( see instructions on their website). Frankly, I've tried to do that recently but failed, especially under Windows although I don't have any experience in this so you can try yourself.
2. Use precompiled library available in some Linux repositories. I had success with Slacko Puppy linux. Package simply adds libstk.a (linux static library) to /usr/lib and stk headers to /usr/include/stk (notice you have to add exactly that path to compiler, since /usr/lib is not enough). This gave me best results.
3. If you use only several classes, you can copy their .cpp files directly to your project source folder. Remember to add parent classes, too (see STK site -> Classes). Again I recommend that you give the compiler path to include folder you've unzipped, but copying only selected headers should also work.
I've found this article helpful (see also A1): http://www.learncpp.com/cpp-tutorial/a3-using-libraries-with-codeblocks/
Hope I've helped
In this instance I'm using c with autoconf, but the question applies elsewhere.
I have a glade xml file that is needed at runtime, and I have to tell the application where it is. I'm using autoconf to define a variable in my code that points to the "specified prefix directory"/app-name/glade. But that only begins to work once the application is installed. What if I want to run the program before that point? Is there a standard way to determine what paths should be checked for application data?
Thanks
Thanks for the responses. To clarify, I don't need to know where the app data is installed (eg by searching in /usr,usr/local,etc etc), the configure script does that. The problem was more determining whether the app has been installed yet. I guess I'll just check in install location first, and if not then in "./src/foo.glade".
I dont think there's any standard way on how to locate such data.
I'd personally do it in a way that i'd have a list of paths and i'd locate if i can find the file from anyone of those and the list should containt the DATADIR+APPNAME defined from autoconf and CURRENTDIRECTORY+POSSIBLE_PREFIX where prefix might be some folder from your build root.
But in any case, dont forget to use those defines from autoconf for your data files, those make your software easier to package (like deb/rpm)
There is no prescription how this should be done in general, but Debian packagers usually installs the application data somewhere in /usr/share, /usr/lib, et cetera. They may also patch the software to make it read from appropriate locations. You can see the Debian policy for more information.
I can however say a few words how I do it. First, I don't expect to find the file in a single directory; I first create a list of directories that I iterate through in my wrapper around fopen(). This is the order in which I believe the file reading should be done:
current directory (obviously)
~/.program-name
$(datadir)/program-name
$(datadir) is a variable you can use in Makefile.am. Example:
AM_CPPFLAGS = $(ASSERT_FLAGS) $(DEBUG_FLAGS) $(SDLGFX_FLAGS) $(OPENGL_FLAGS) -DDESTDIRS=\"$(prefix):$(datadir)/:$(datadir)/program-name/\"
This of course depends on your output from configure and how your configure.ac looks like.
So, just make a wrapper that will iterate through the locations and get the data from those dirs. Something like a PATH variable, except you implement the iteration.
After writing this post, I noticed I need to clean up our implementation in this project, but it can serve as a nice start. Take a look at our Makefile.am for using $(datadir) and our util.cpp and util.h for a simple wrapper (yatc_fopen()). We also have yatc_find_file() in case some third-party library is doing the fopen()ing, such as SDL_image or libxml2.
If the program is installed globally:
/usr/share/app-name/glade.xml
If you want the program to work without being installed (i.e. just extract a tarball), put it in the program's directory.
I don't think there is a standard way of placing files. I build it into the program, and I don't limit it to one location.
It depends on how much customising of the config file is going to be required.
I start by constructing a list of default directories and work through them until I find an instance of glade.xml and stop looking, or not find it and exit with an error. Good candidates for the default list are /etc, /usr/share/app-name, /usr/local/etc.
If the file is designed to be customizable, before I look through the default directories, I have a list of user files and paths and work through them. If it doesn't find one of the user versions, then I look in the list of default directories. Good candidates for the user config files are ~/.glade.xml or ~/.app-name/glade.xml or ~/.app-name/.glade.xml.