please explain in details and execute the code using linux or ubuntu

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 o hour : list class times room : list classroom location desp: list the description of this course text : list the textbook ref: list the reference books 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 tol : TA's office location toh : TA's office hours tma : TA's email address history : list history of events up to the number you set help : list all the available commands exit or quit : exit OS shell o o o o o o o O 0 0 0 0 0 0 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 o hour : list class times room : list classroom location desp: list the description of this course text : list the textbook ref: list the reference books 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 tol : TA's office location toh : TA's office hours tma : TA's email address history : list history of events up to the number you set help : list all the available commands exit or quit : exit OS shell o o o o o o o O 0 0 0 0 0 0