陆续补充，未完待续 …

一、编译环境

1. 查看当前头文件默认搜索路径

• 操作命令

  cpp -v

• 执行效果

  Using built-in specs.
  COLLECT_GCC=cpp
  Target: x86_64-linux-gnu
  Thread model: posix
  gcc version 6.3.0 20170516 (Debian 6.3.0-18+deb9u1) 
  COLLECT_GCC_OPTIONS='-E' '-v' '-mtune=generic' '-march=x86-64'
  ...
  #include "..." search starts here:
  #include <...> search starts here:
  /usr/lib/gcc/x86_64-linux-gnu/6/include
  /usr/local/include
  /usr/lib/gcc/x86_64-linux-gnu/6/include-fixed
  /usr/include/x86_64-linux-gnu
  /usr/include
  End of search list.