zero 、 Basic knowledge
（1） The environment ： Newly installed on Baidu ECS centos7.4 System
（2） Common code ：
tar zxvf filename.tar #tar Unpack
tar czvf filename.tar dirname #tar pack
One 、 install cmake
（1） Download url ：https://cmake.org/files/v3.10/cmake-3.10.3-Linux-x86_64.sh, Copy cmake-3.10.3-Linux-x86_64.sh To /home/backup Next .
（2）sudo sh cmake-3.10.3-Linux-x86_64.sh --prefix=/usr/local --exclude-subdir
（3） Check version
Use cmake -version see cmake edition
Use ccmake -version see ccmake edition
（4） remarks , uninstall cmake（ unsuccessful , Be careful ）
find make install The file that came out after that install_manifest.txt
There is a path to everything installed , Just delete them .
Refer to the order ：cat install_manifest.txt | sudo xargs rm
Verify that the command is uninstalled ：sudo yum remove cmake
Uninstall the original cmake ： yum -y remove cmake
Search for ： find / -name cmake ( Delete all the items found )
Two 、 install python2 Related plug-ins
at present python2 Not pre installed in pip command , So you need to install it yourself pip command , Easy to install python Various packages used .
（1） First, check whether it is installed python-pip, You can execute commands directly yum install python-pip
（2） If an error is reported in the previous step , It has to be executed first yum -y install epel-release; success epel Post execution yum install python-pip It can be installed normally pip
（3） installed python-pip Finally, execute the upgrade command : pip2 install --upgrade pip
（4） To validate the pip2 Is it available , Executable command pip2 install requests install requests package
3、 ... and 、 install anaconda
（1） take Anaconda3-5.2.0-Linux-x86_64.sh Put in /home/backup in . function sh Anaconda3-5.2.0-Linux-x86_64.sh, Installation location selection /opt/install/anaconda3.
（2）Do you wish the installer to prepend the Anaconda3 install location to PATH in your /root/.bashrc ?[yes|no]. choose yes. If there is no choice , Add it yourself later .
（3）Do you wish to proceed with the installation of Microsoft VSCode? [yes|no]. Not usually used , choose ”no”
（4）source /root/.bashrc
（5） Verify availability : python. sign out python Program , Input required :exit()
Four 、 Source code compilation and installation opencv
（1）yum update
（2）gcc upgrade
yum -y install centos-release-scl
yum -y install devtoolset-6-gcc devtoolset-6-gcc-c++ devtoolset-6-binutils
scl enable devtoolset-6 bash
It should be noted that scl Command activation is only temporary , sign out shell Or restart will restore the original system gcc edition . If you want to use it for a long time gcc 6.3 Words ：
echo "source /opt/rh/devtoolset-6/enable" >>/etc/profile
（3）essential install
yum install kernel-devel # install gcc-essential
yum install gcc-gfortran # install gfortran
After the installation , It can be used gcc -v 、g++ -v and fortran -v View version .
（4）gtk2.0 install
yum install git # install git
yum install libgnomeui-devel # Install the necessary packages （gtk Graphical interface library ）
yum install gtk2 gtk2-devel gtk2-devel-docs # Install the necessary components
yum install gnome-devel gnome-devel-docs # Install optional components
（5）pkg-config install
Usually the computer comes with it , View version ：pkg-config --version
（6）ffmpeg Component installation . Mostly used for video processing , Proposed installation
install epel Extended source ：yum -y install epel-release
Install extension source
yum localinstall --nogpgcheck https://download1.rpmfusion.org/free/el/rpmfusion-free-release-7.noarch.rpm https://download1.rpmfusion.org/nonfree/el/rpmfusion-nonfree-release-7.noarch.rpm
rpm --import http://li.nux.ro/download/nux/RPM-GPG-KEY-nux.ro
rpm -Uvh http://li.nux.ro/download/nux/dextop/el7/x86_64/nux-dextop-release-0-1.el7.nux.noarch.rpm
yum -y install ffmpeg ffmpeg-devel # install ffmpeg rely on
test ffmpeg Has it been installed successfully? : ffmpeg -version
（7） install opencv Other dependencies :
yum install python-devel numpy
yum install libdc1394-devel
yum install libv4l-devel
yum install gstreamer-plugins-base-devel
yum -y install ant( install ant, Tears recommendation )
（8） compile opencv
hold opencv-3.4.5.zip Copied to the /root below . Then unzip and enter :unzip opencv-3.4.5.zip
cd opencv-3.4.5
mkdir build
cd build
cmake -D CMAKE_BUILD_TYPE=Release -D CMAKE_INSTALL_PREFIX=/usr/local/opencv3 ..
Pay attention to the compilation information , Installed here python2 edition .
-- Found PythonInterp: /usr/bin/python2.7 (found suitable version "2.7.5", minimum required is "2.7")
-- Found PythonLibs: /lib64/libpython2.7.so (found suitable exact version "2.7.5")
-- Found PythonInterp: /root/anaconda3/bin/python3 (found suitable version "3.6.5", minimum required is "3.2")
-- Could NOT find PythonLibs (missing: PYTHON_LIBRARIES PYTHON_INCLUDE_DIRS) (Required is exact version "3.6.5")
-- Looking for ccache - not found
Above if CMAKE_INSTALL_PREFIX The installation directory is not specified , The default is to install to /usr/local Put it together with the system （ It is recommended to default to , Non default is not responsible ）, After that, you can view the relevant supported extensions , No problem compiling and installing ：
make
make install
（9）opencv Configure and load dynamic libraries
（9.1） Path addition and loading :
Enter target file : cd /etc/ld.so.conf.d
add to opencv.conf file : touch opencv.conf
add to opencv Compiled lib Library path to opencv.conf in , Following commands ：
/bin/bash -c 'echo "/usr/local/opencv3/lib64" > /etc/ld.so.conf.d/opencv.conf'
load : sudo ldconfig
Be careful : Among others linux There may be differences in the system , But it is intended to let the system know opencv lib The path of the library , Can complete dynamic loading .
（9.2） add to PATH
Enter the command vi /etc/bashrc
Add a new line at the end of the document export PKG_CONFIG_PATH=/usr/lib64/pkgconfig:/$PKG_CONFIG_PATH
Save and exit
Input source /etc/bashrc Make configuration effective
Input updatedb Update the database
（9.3）pkg-config To configure
default pkg Search link path /usr/lib64/pkgconfig. Need to put opencv.pc copy to pkg Under the default path of .
cp /usr/local/opencv3/lib64/pkgconfig/opencv.pc /usr/lib64/pkgconfig
5、 ... and 、 install pytorch and libtorch
conda install pytorch-cpu==1.0.0 torchvision-cpu==0.2.1 cpuonly -c pytorch # Because it comes with python-3.6.6 edition . So I doubt what I used to pretend anaconda It doesn't work .
https://download.pytorch.org/libtorch/cpu/libtorch-win-shared-with-deps-1.3.1.zip # Put it in /opt/install
6、 ... and 、 Other preparations
yum install gperftools-libs # This is not necessary
7、 ... and 、 Operation example
（7.1） Run the command
cmake -DCMAKE_PREFIX_PATH=/opt/install/libtorch .. # See you for finished products route /home/project/example04/example-app08/build
8、 ... and 、 see python2 Configuration of , Prepare to compile
（8.1） The system configuration
locate python2.7-config # In the first place to find python2.7-config The location of
/usr/bin/python2.7-config --cflags #pythonX.Y-config --cflags will give you the recommended flags when compiling
/usr/bin/python2.7-config --ldflags #pythonX.Y-config --ldflags will give you the recommended flags when linking
（8.2）CMakeLists Content
cmake_minimum_required(VERSION 3.0 FATAL_ERROR)
project(custom_ops)
include_directories(/usr/include/python2.7)
link_directories(/usr/lib64/python2.7/config)
add_executable(example-app example-app.cpp)
target_link_libraries(example-app python2.7)
set_property(TARGET example-app PROPERTY CXX_STANDARD 11)
（8.3）example-app.cpp Remember to add initialization
PyRun_SimpleString("import sys");
PyRun_SimpleString("print '---import sys---'");
PyRun_SimpleString("sys.path.append('../')");
（8.4） stay build Command under folder ：
./example-app multiply multiply 3 3
（8.5）pip2 install pillow/numpy
