Please answer with explanations

execute it using linux or ubuntu

Question 1 A. Write a simple shell script to move (rename) all * MP3 files under the current directory (if any) to *.mp3, e.g., move test. MP3 to test.mp3 move hello.MP3.MP3 to hello.MP3.mp3 move .hello.MP3.MP3 to.hello.MP3.mp3 and report each action, otherwise just report there are no * MP3 files. B. In c++: Write a simple single thread OS shell, i.e., no concurrent commands, to support at least the following built-in commands: prompt can set to any string you input, in addition to the current history event number, i.e, %h as in csh; url : list the course web site hour : list class times room : list classroom location desp: list the description of this course text : list the textbook ref: list the reference books o prof: list the professor's name o pol : professor's office location poh : professor's office hours pma : professor's email address ta : list the TA's name o tol : TA's office location o toh : TA's office hours tma : TA's email address history : list history of events up to the number you set o help : list all the available commands exit or quit : exit OS shell 0 0 0 0 0 0 o o o o o o o o o