【原创】【源代码】myshell：操作系统编程-自己用C语言写的Linux下的Shell

【文件格式是Linux下的gz压缩包，在Windows下可以用WinRAR解压】 本人原创的操作系统上机作业（源代码），自己编写一个简单的Linux下的shell（a simple myshell）！原题见William Stallings写的《Operating Systems - Internals and Design Principles》（操作系统--内核与设计原则）： The shell must support the following internal commands: cd - change the current default directory to . If the argument is not present, report the current directory. If the directory does not exist an appropriate error should be reported. This command should also change the PWD environment variable. clr - clear the screen. dir - list the contents of directory environ - list all the environment strings echo - display on the display followed by a new line (multiple spaces/tabs may be reduced to a single space) help - display the user manual using the more filter pause - pause operation of the shell until 'Enter' is pressed quit - quit the shell The shell environment should contain shell=/myshell where /myshell is the full path for the shell executable (not a hardwired path back to your directory, but the one from which it was executed)