I am trying to compile a C++ code in a Ubuntu 12.04 OS using a make file. My code requires libxml2 and sqlite3. I have installed the packages using the Synaptics Package manager. However, now I do not know the path of the header(.h) files and shared object library (.so) files.
Is there a default location for these?
Thanks
There are default locations -- /usr/include for headers, /usr/lib for libraries -- meaning that you do not have to specify them in the Makefile.
But do make sure you have the corresponding -dev packages libsqlite3-dev and libxml2-dev installed!
Related
I am using OpenCV in one of my projects. Until now, I was using version 3 under Ubuntu 18.04, so in my meson.build I had:
... dependencies: [dependency('opencv')])
Now, I've compiled OpenCV 4 from source and installed to the default dir, /usr/local/, and changed my meson.build to:
... dependencies: [dependency('opencv4')])
Resulting in a not found error (despite this works with Ubuntu 20.04 and the package from the official repos, which is version 4.2). How should I specify the library's location so Meson can find it?
I've seen find_library, but that's deprecated according the docs.
The dependency function is using pkg-config or cmake if pkg-config fails, to find external dependency (installed library).
When you install OpenCV4, please check if there is pkg-config for opencv4. Here is my command:
pkg-config --list-all | grep "opencv4"
and output:
opencv4 OpenCV - Open Source Computer Vision Library
Also, check PKG_CONFIG_PATH environment variable. pkg-config will use that path to search for .pc files.
Edit:
be sure to use -D OPENCV_GENERATE_PKGCONFIG=YES when building opencv with cmake.
Basically I am developing a project using OpenVino and OpenCV,to do so I cannot use the normal and easy way of using pip to install opencv library but instead Intel provided their own optimized version OpenCV.
I cannot find a place to add the path for the custom OpenCV in pycharm.
If anybody can enlighten me,please do so.
Thank you in advance.
please try the below steps.
Install Python 2.7.10
Install Pycharm(If not installed previously)
Download the OpenCV executable.
Install OpenCV
Add OpenCV in the system path(%OPENCV_DIR% = /path/of/opencv/directory)
Goto C:\opencv\build\python\2.7\x86 folder and copy cv2.pyd file.
Goto C:\Python27\DLLs directory and paste the cv2.pyd file.
Goto C:\Python27\Lib\site-packages directory and paste the cv2.pyd file.
Goto PyCharm IDE and goto DefaultSettings>PythonInterpreter.
Select the Python which you have installed on Step1.
Install the packages numpy,matplotlib and pip in pycharm.
Restart your PyCharm.
PyCharm now has OpenCV library installed and working.
Hope this will solve your issue
on luarocks install lyaml I get following error:
Error: Could not find expected file libyaml.a, or libyaml.so, or libyaml.so.* for YAML -- you may have to install YAML in your system and/or pass YAML_DIR or YAML_LIBDIR to the luarocks command. Example: luarocks install lyaml YAML_DIR=/usr/local
lua version: 5.1.5
How do I install YAML in system to start using lyaml rock?
Whenever you get a LuaRocks message saying you may have to install ____ in your system it means the rockspec has an external dependency.
Installing external dependencies
The way to satisfy this dependency is to install the package using the appropriate means of your system: if using Debian/Ubuntu, with apt-get, if using macOS, probably using Homebrew, etc.
Note that for building code, in systems that have the concept of dev packages, such as most Linux distributions, you need to install both the main library package and the dev package (which contains the header files for compilation). For example, for Debian/Ubuntu, to satisfy this dependency you need to run apt-get install libyaml libyaml-dev.
Unfortunately, the names are not fully consistent across systems and distros: a module may be called ncurses-dev in one system, libncurses6w-dev in another, etc. So in your particular case you'll have to search around for the right name of the YAML library (the package providing libyaml) in your system.
Once the external dependency is installed...
Installing a library with the system package manager will usually install the necessary files in locations that are automatically detected by LuaRocks, so running
luarocks install lyaml
again should find the libyaml files and proceed with the installation.
If external dependencies are installed in a non-standard location
If that fails, you can find the directories where the library (libyaml.so) and header (yaml.h) were installed and tell LuaRocks about it. For example, if libyaml.so was installed in some non-standard locations such as /opt/lib/yaml/libyaml.so and the header in /opt/include/yaml-1/yaml.h you would do this:
luarocks install lyaml YAML_LIBDIR=/opt/lib/yaml/ YAML_INCDIR=/opt/include/yaml-1/
This kind of situation happens when a system installs headers or libraries in a subdirectory. For example, for LuaSec on the Mac, which uses OpenSSL, it is sometimes necessary to use pathnames like this:
luarocks install luasec OPENSSL_INCDIR=/usr/local/opt/openssl/include OPENSSL_LIBDIR=/usr/local/opt/openssl/lib
I have installed MSYS2 along with mingw64 on windows.
How do I install an application or library (in this case OpenCV) from the source code into mingw64 in the same way as pacman does, ideally using the CMAKE-GUI (due to a number of options to set)?
I have tried using
Use CMake-Gui to generate a mingw-makefile, with an additional DCMAKE_INSTALL_PREFIX:PATH entry.
Running mingw64 make installed
The code compiles fine but then installing into the CMAKe build directory4
MSYS pkg-manager can not see the library (opencv)
pacman for MSYS2 is an MSYS2 port of the ArchLinux package manager,
pacman.
To make an application or library installable "in the same way as pacman",
and so that pacman can see it, you need to make a pacman package
of it: here is the documentation
I am writing a small Lua project and using Luarocks to install my 3rd-party dependencies. The default Lua version on my machine is 5.2 and up to this point everything is working just fine.
However, today I have stumbled across a problem that is confusing me. I want to run my program on Lua 5.1 and Luajit to see if it would also work on those versions but I am having a hard time getting Luarocks to download the appropriate versions of the dependencies. As a last resort hack, I have tried to tell Lua5.1 to use the 5.2 libraries that Luarocks installed (by setting the LUA_PATH environment variable to the same value as LUA_PATH_5_2) but unfortunately that is not enough: my project depends on LuaFileSystem, a C-based module, so I'm going to need to have separate versions of it installed for 5.1 and 5.2.
What do I have to do to install both the 5.1 and 5.2 versions of my dependencies? Do I need to pass some parameters to theluarocks install command? Do I need to have multiple instances of Luarocks installed on my machine? One thing that confuses me is that the inside the .luarocks folder things are classified under a 5.2 subfolder (~/.luarocks/share/lua/5.2/), suggesting that maybe there could be a way to install things in a sibling 5.1 folder but at the same time there is only one bin folder, suggesting that luarocks is only able to handle one version of Lua at a time...
Based on your reference to ~/.luarocks/share/lua/5.2/, you seem to be running a Unix system (Linux or Mac). You can install the latest version of LuaRocks twice, for both Lua 5.1 and Lua 5.2 like this:
./configure --lua-version=5.1 --versioned-rocks-dir
make build
sudo make install
And then again for 5.2:
./configure --lua-version=5.2 --versioned-rocks-dir
make build
sudo make install
This will get you /usr/local/bin/luarocks-5.1 and /usr/local/bin/luarocks-5.2. If you installed Lua 5.1 and 5.2 in /usr/local/, and each of them will use its own ~/.luarocks/lib/luarocks/rocks-5.x/ entry for the user tree (and /usr/local/lib/luarocks/rocks-5.x for the system tree), and install modules to the right location at /usr/share/lua/5.x/ and ~/.luarocks/share/lua/5.x/ (and likewise for lib) appropriately.
As suggested by moteus, I decided to install a second version of Luarocks for Lua 5.1. But he is using Windows and I am using Linux so here is what I did:
Download the source for the latest version of Luarocks on the Luarocks website
From the source directory, run the ./configure script:
/configure --prefix="${HOME}/.luarocks51" --lua-suffix=5.1
The prefix setting tells Luarocks to put its stuff on the .luarocks51 folder, next to the existing .luarocks folder from my 5.2 install of Luarocks. The lua-suffix parameter tells Luarocks to use Lua 5.1 instead of the default lua version in my machine (5.2). This depends on me having named the interpreter for Lua 5.1 as lua5.1 (Debian installed mine on /usr/bin/lua5.1). Finally, Luarocks managed to automatically detect where the 5.1 headers and libraries are installed (/usr/include/lua5.1/) but if it didn't I guess I could have specified that with the --with-lua-include and --with-lua-lib parameters.
Compile Luarocks with make
Install it with make isntall (no need for Sudo since I'm installing it in a local directory).
Configure my 5.1 environment to use the libraries downloaded by Luarocks. I added the following to my .bashrc:
export PATH=$PATH:~/.luarocks/bin:~/.luarocks51/bin
export LUA_CPATH=";;${HOME}/.luarocks51/lib/lua/5.1/?.so"
export LUA_PATH=";;${HOME}/.luarocks51/share/lua/5.1/?.lua;${HOME}/.luarocks51/share/lua/5.1/?/init.lua"
export LUA_CPATH_5_2=";;${HOME}/.luarocks/lib/lua/5.2/?.so"
export LUA_PATH_5_2=";;${HOME}/.luarocks/share/lua/5.2/?.lua;${HOME}/.luarocks/share/lua/5.2/?/init.lua"
The 5.1 configuration also works for Luajit.
The executable for the 5.1 version of luarocks is named luarocks-5.1:
luarocks-5.1 install lfs
You have to mention both lua version and lua dir in the latest versions:
luarocks --lua-dir=$(brew --prefix)/opt/lua#5.1 --lua-version=5.1 install lua-cassandra
Using homebrew, you can do:
brew install lua51 # Lua 5.1
brew install lua # Lua latest
Luarocks comes with Lua, so you can do:
# Install Lua 5.1 version of any package
luarocks-5.1 install moonscript
# Install Lua latest version of any package
luarocks install moonscript