C++ Program to emulate a basic shell script. Commands are as follows:
- quit ends program
- date displays current date and time
- curr displays absolute pathname of current dir
- env display all of the environment variables
- cd moves current directory to given dir
- hlist display recent commands (up to 10)
- dlist display recent directories (up to 10)
- !N displays and executes command at line N if in hlist
- #N move to directory at given index in dlist