Basic code of a shell. commands like ls,cd,echo,pwd work and code is written for the same.

ls - It can be used with flags -l,-a,-la,-al,-l -a,ls <directory_name>. cd - command to change directory echo - Echo command can be used without quotes pwd - will give you present working directory The commands are ';' tokenised so more than one command can be executed using same command line input. Pinfo- will give you the process info about the present executing process. Pinfo PID will give you pinfo about the process whose ID was given. With any process executed with '&' at last process will be executed in the background.

The functions for every of these command are made in the code. Every other command is considered as a system command.