Introduction The shell is the primary means for user interaction with a Unix system. The shell is a program like any other program and has the capabilities built into the logic to implement the functionality users require. Assignment Description This assignment is to write a shell program which will implement 7 commands: 1) the echo command, 2) the PS1 prompt command, 3) the cat command, 4) the cp file command, 5) the rm file command 6) the mkdir directory command and 7) the rmdir directory command. Program Requirements 1. The student will create an application which will implement a command loop and accept the commands defined by the following requirements. These will be builtin commands. 2. The student will implement the echo command to display its argument to the console. It will assume a carriage return. If the option -n is entered the carriage return will not be issued. 3. The student will implement the PS1 command to change the display of the prompt. The initial prompt will be the $ . 4. The student will implement the cat command to display the contents of a file. 5. The student will implement the cp command to copy the contents of a file. 6. The student will implement the rm command to delete the file. 7. The student will implement the mkdir command to create a directory. 8. The student will implement the rmdir command to delete the directory. 9. The student will implement the exit command to exit mysh. 10. If an incorrect command is entered a Usage message will be displayed and the prompt will be redisplayed. 11. The student is required to use the -ansi option to gcc for this assignment. 12. The student is required to put their name at the top of the .c source file. 13. The name of the program will be mysh, an abbreviation of my shell. The program must be written in C and named mysh.c. 14. The student will tar the program. The tar command for the C program is: $ tar czf studentlastname_mysh.tgz mysh.c