在非GUI环境下，需要用户输入的程序就免不了使用命令行，命令行要写得好可不容易。readline提供了几乎你能想到的所有命令行功能。这个版本是linux/unix通用平台，并可方便的移植到其它平台（实际上它与操作系统关联不大）。-in non - GUI environment, the need for user input on the process will inevitably use the command line, the command line is difficult to write well. Readline provided you can think of almost all the command line functions. This version of linux / unix common platform, convenience may migrate to other platforms (it not associated with the operating system).