Ubuntu上安装cmake

1. 安装以下库      （1）sudo apt-get install build-essential 

        (不装会报makefile找不到，Cannot find appropriate Makefile processor on this system）

     （2）sudo apt-get install libssl-dev

-- Could NOT find OpenSSL, try to set the path to OpenSSL root folder in the system variable OPENSSL_ROOT_DIR (missing: OPENSSL_CRYPTO_LIBRARY OPENSSL_INCLUDE_DIR) 
CMake Error at Utilities/cmcurl/CMakeLists.txt:562 (message):
  Could not find OpenSSL.  Install an OpenSSL development package or
  configure CMake with -DCMAKE_USE_OPENSSL=OFF to build without OpenSSL.

   (3) sudo install ncurses-dev 2.  从官网下载最新Linux版的cmake工具源码，然后解压，进入源码根目录，执行：

       ./bootstrap && make

        sudo make install

3. 安装完毕

注意事项：

    编译cmake时，源码不能放在挂载(mount)的盘上，比如用Linux虚拟机编译cmake，cmake源码放在window里某个目录，编译时会报如下错误：

The C++ compiler does not support C++11 (e.g.  std::unique_ptr).

解决方法：

   1. 将cmake源码copy到linux的某个目录下，比如/home/works下

   2. 清除上次执行./bootstrap生成的中间文件

        rm -r CMakeCache.txt CMakeFiles/ Bootstrap.cmk/

       不清除可能会报如下错误：                        

CMake 3.16.5, Copyright 2000-2019 Kitware, Inc. and Contributors
Found GNU toolchain
C compiler on this system is: gcc  
C++ compiler on this system is: g++  -std=gnu++17  
Makefile processor on this system is: make
g++ has setenv
g++ has unsetenv
g++ does not have environ in stdlib.h
g++ has stl wstring
g++ has 

   3. 重新编译cmake