使用简单方便，可以跨平台，构建项目编译环境。尤其比直接写Makefile简单（在构建大型工程编译时，需要写大量的文件依赖关系），可以通过简单的CMake生成负责的Makefile文件。
ubuntu上直接执行 sudo apt install cmake 安装完成，可以通过cmake -version查看其版本：
cmake命令会执行目录下的CMakeLists.txt配置文件里面的配置项，一个基本的CMakeLists.txt的配置文件内容如下：
cmake_minimum_required (VERSION 2.8) #要求cmake最低的版本号 project (demo) # 定义当前工程名字 # 设置debug模式，如果没有这一行将不能调试设断点 set(CMAKE_BUILD_TYPE "Debug") # 有了这个编译文件就可以进行调试了 可以是-g -O2 等 set(CMAKE_CXX_FLAGS ${CMAKE_CXX_FLAGS} -g) # 添加可执行文件 和 生成可执行文件的依赖项(main.c) add_executable(main main.c) # 进入子目录下执行 CMakeLists.txt文件 这里的lib和tests里面都有可编译的代码文件 add_subdirectory(lib) add_subdirectory(tests)保存退出，执行cmake . 命令，输出如下：
tony@tony-virtual-machine:~/code/cmake/rpc$ cmake . -- The C compiler identification is GNU 7.4.0 -- The CXX compiler identification is GNU 7.4.0 -- Check for working C compiler: /usr/bin/cc -- Check for working C compiler: /usr/bin/cc -- works -- Detecting C compiler ABI info -- Detecting C compiler ABI info - done -- Detecting C compile features -- Detecting C compile features - done -- Check for working CXX compiler: /usr/bin/c++ -- Check for working CXX compiler: /usr/bin/c++ -- works -- Detecting CXX compiler ABI info -- Detecting CXX compiler ABI info - done -- Detecting CXX compile features -- Detecting CXX compile features - done -- Configuring done -- Generating done -- Build files have been written to: /home/tony/code/cmake/rpcls查看目录，发现除了CMake生成的一些中间文件，还生成好了Makefile文件
tony@tony-virtual-machine:~/code/cmake/rpc$ ls CMakeCache.txt CMakeFiles cmake_install.cmake CMakeLists.txt main.cpp Makefilemake开始编译，最终生成可执行文件main
tony@tony-virtual-machine:~/code/cmake/rpc$ make Scanning dependencies of target main [ 50%] Building CXX object CMakeFiles/main.dir/main.cpp.o [100%] Linking CXX executable main [100%] Built target main查看生成的可执行文件：
tony@tony-virtual-machine:~/code/cmake/rpc$ ls CMakeCache.txt CMakeFiles cmake_install.cmake CMakeLists.txt main main.cpp Makefile上面生成的Makefile里面实现了clean，所以make clean可以清除生成的文件，然后重新编译源码。
如果需要编译的有多个源文件，可以都添加到add_executable(main main.cpp test.cpp)列表当中，但是如果源文件太多，一个个添加到add_executable的源文件列表中，就太麻烦了，此时可以用aux_source_directory(dir var) 来定义源文件列表，使用如下：
cmake_minimum_required (VERSION 2.8) project (demo) aux_source_directory(. SRC_LIST) # 定义变量，存储当前目录下的所有源文件 add_executable(main ${SRC_LIST}) #SRC_LIST变量就代表了所有源文件aux_source_directory()也存在弊端，它会把指定目录下的所有源文件都加进来，可能会加入一些我们不需要的文件，此时我们可以使用set命令去新建变量来存放需要的源文件，如下：
cmake_minimum_required (VERSION 2.8) project (demo) set( SRC_LIST ./main.cpp ./test.cpp) # 用 set 指定这两个 add_executable(main ${SRC_LIST})一个正式的源码工程应该有这几个目录：
-bin 存放最终的可执行文件 -build 存放编译生成的中间文件 -include 存放头文件 --sum.h --minor.h -src 存放源文件 --sum.cpp --minor.cpp mian.cpp -CMakeLists.txtCMakeLists.txt 的构建如下：
cmake_minimum_required (VERSION 2.8) project (math) #设置cmake的全局变量,生成的可执行文件放在/bin目录下 set(EXECUTABLE_OUTPUT_PATH ${PROJECT_SOURCE_DIR}/bin) #添加头文件路径，相当于makefile里面的-I include_directories(${PROJECT_SOURCE_DIR}/include) aux_source_directory (src SRC_LIST) add_executable (main main.cpp ${SRC_LIST})然后在build目录里面执行cmake .. 命令，这样所有的编译中间文件都会在build目录下，最终的可执行文件会在bin目录里面
tony@tony-virtual-machine:~/code/cmake/rpc/build$ cmake .. -- The C compiler identification is GNU 7.4.0 -- The CXX compiler identification is GNU 7.4.0 -- Check for working C compiler: /usr/bin/cc -- Check for working C compiler: /usr/bin/cc -- works -- Detecting C compiler ABI info -- Detecting C compiler ABI info - done -- Detecting C compile features -- Detecting C compile features - done -- Check for working CXX compiler: /usr/bin/c++ -- Check for working CXX compiler: /usr/bin/c++ -- works -- Detecting CXX compiler ABI info -- Detecting CXX compiler ABI info - done -- Detecting CXX compile features -- Detecting CXX compile features - done -- Configuring done -- Generating done -- Build files have been written to: /home/tony/code/cmake/rpc/build tony@tony-virtual-machine:~/code/cmake/rpc/build$ make Scanning dependencies of target main [ 25%] Building CXX object CMakeFiles/main.dir/main.cpp.o [ 50%] Building CXX object CMakeFiles/main.dir/src/minor.cpp.o [ 75%] Building CXX object CMakeFiles/main.dir/src/sum.cpp.o [100%] Linking CXX executable ../bin/main [100%] Built target main tony@tony-virtual-machine:~/code/cmake/rpc$ cd bin/ tony@tony-virtual-machine:~/code/cmake/rpc/bin$ ls main最外层的CMakeLists.txt是总控制编译，内容如下：
cmake_minimum_required (VERSION 2.8) project (math) add_subdirectory (test) add_subdirectory (src)src里面的源代码要生成静态库或动态库，CMakeLists.txt内容如下：
set (LIBRARY_OUTPUT_PATH ${PROJECT_SOURCE_DIR}/lib) #生成库，动态库是SHARED，静态库是STATIC add_library (sum SHARED sum.cpp) add_library (minor SHARED minor.cpp) #修改库的名字 #set_target_properties (sum PROPERTIES OUTPUT_NAME "libsum") #set_target_properties (minor PROPERTIES OUTPUT_NAME "libminor")test里面的CMakeLists.txt内容如下：
set (EXECUTABLE_OUTPUT_PATH ${PROJECT_SOURCE_DIR}/bin) include_directories (../include) # 头文件搜索路径 link_directories (${PROJECT_SOURCE_DIR}/lib) # 库文件搜索路径 add_executable (main main.cpp) # 指定生成的可执行文件 # 执行可执行文件需要依赖的库 target_link_libraries (main sum minor)在build目录下执行cmake …命令，然后执行make，如下:
tony@tony-virtual-machine:~/code/cmake/rpc02/build$ make [ 16%] Building CXX object src/CMakeFiles/minor.dir/minor.cpp.o [ 33%] Linking CXX shared library ../../lib/libminor.so [ 33%] Built target minor [ 50%] Building CXX object src/CMakeFiles/sum.dir/sum.cpp.o [ 66%] Linking CXX shared library ../../lib/libsum.so [ 66%] Built target sum Scanning dependencies of target main [ 83%] Building CXX object test/CMakeFiles/main.dir/main.cpp.o [100%] Linking CXX executable ../../bin/main [100%] Built target main查看生成的可执行文件，检验其链接的库有哪些:
tony@tony-virtual-machine:~/code/cmake/rpc02/bin$ ls main tony@tony-virtual-machine:~/code/cmake/rpc02/bin$ ./main 20 + 10 = 30 20 - 10 = 10 tony@tony-virtual-machine:~/code/cmake/rpc02/bin$ readelf -d ./main Dynamic section at offset 0x1d48 contains 31 entries: 标记 类型 名称/值 0x0000000000000001 (NEEDED) 共享库：[libsum.so] 0x0000000000000001 (NEEDED) 共享库：[libminor.so] 0x0000000000000001 (NEEDED) 共享库：[libstdc++.so.6] 0x0000000000000001 (NEEDED) 共享库：[libc.so.6]