早期的软件开发基于命令行（command line）模式，调用各种命令完成代码的编译（compile）、连接（link）、运行（execute）及环境的配置（config）等--Early software development based on the command line (command line) mode, all commands to complete the code calling compile (compile), connect (link), run (execute) and the environment configuration (config), etc.