Its a user defined shell, implemented in C language using the POSIX library.

Download the code and compile and run the code using -

> gcc shell.c -o terminal

> ./terminal

Commands -

(The following commands are supported)

1. ls, ps ,ps -aux, find etc - All Linux shell commands are run

2. Redirection to file or to other commands; eg : ls > log or ls | sort

3. Process ID related commands:

   a) pid all : gives PID of all commands run till now from the terminal

   b) pid current : gives list of currently running child processes

   c) pid : gives pid of present process (./a.out's pid )

4. History related commands :

   a) hist : Gives a history of all the commands run till now

   b) histN : Gives list of the last N commands

   c) !histN : runs the Nth command

5. Background processes are also supported; Eg: emacs &