Cmake学习笔记（四）find类指令 以FIND

指令 以FIND"/>

Cmake学习笔记（四）find类指令 以FIND

Cmake Find类指令

以FIND_PACKAGE()为例，我们用OpenCV为实例来看

我们需要为工程设置依赖的头文件和库时，往往需要以下方法

include_directiories(../include)
target_link_libraries(proTest ../OpenCV)

但是，opencv需要以来的动态库有时非常多，那我们一个个路径来配置么，肯定会比较麻烦，这时就会需要FIND_PACKAGE。先看实际应用怎么写，我们

set(OpenCV_DIR "D:\\opencv\\opencv\\build\\x86\\vc12\\lib\\")
find_package(OpenCV REQUIRED)
include_directories(${OpenCV_INCLUDE_DIRS})
target_link_libraries(curltest ${OpenCV_LIBRARY})

首先设置opencv的安装路径，紧接着，通过find_package来自动查找，包含的动态库和头文件所需信息，注意OpenCV是cmake预置变量，内部客人，在linux下一定注意大小写。

Cmake会根据你配置的路径，文件夹中去OpenCVConfig.cmake，OpenCV-config.cmake 两个文件，进而确定你要引入的opencv头文件和库函数在哪里

对OpenCV还有一些有些变量，对编写CmakeList有用，必如OpenCV_FOUND可以用来标记是否找到响应文件和信息。
那我们CmakeList就可以改写成

project(HELLO)
set(SRC_LIST CmakeHelloWord.cpp)
#set (CMAKE_PREFIX_PATH "D:\\QT\\5.8\\msvc2015\\")add_executable(hello ${SRC_LIST})set(OpenCV_DIR "D:\\opencv\\opencv\\build\\x86\\vc12\\lib\\")
find_package(OpenCV REQUIRED)
if(OpenCV_FOUND)
MESSAGE(STATUS "OpenCV_VERSION: ${OpenCV_VERSION}")
MESSAGE(STATUS "OpenCV_INCLUDE_DIRS: ${OpenCV_INCLUDE_DIRS}")
MESSAGE(STATUS "OpenCV_LIBS: ${OpenCV_LIBS}")
include_directories(${OpenCV_INCLUDE_DIRS})
target_link_libraries(curltest ${OpenCV_LIBS})
else(OpenCV_FOUND)
message(FATAL_ERROR "OpenCV not found!")
endif(OpenCV_FOUND)

据说并不是所有的，预置变量都是_INCLUDE_DIRS 和 _LIBS，据说会有如下形式，待验证

• (name)_FOUND
• (name)_INCLUDE_DIR 或 (name)_INCLUDES
• (name)_LIBRARY 或 (name)_LIBRARIES 或 (name)_LIBS
• (name)_DEFINITIONS