简单的 Shell命令解析器的功能，创建子进程，并执行用户的命令，创建历史特性，当用户按下 Ctrl+C 键的时候打印出用户最近输入的10 个命令。包含实验报告-Simple Shell command parser function, creating a child process and execute user commands, to create history characteristics, when the user presses Ctrl+ C key when the user prints out the 10 most recently entered command. The report contains the experimental