Linux

It is a part of implementation of the shell. I call it as "ddsh" -:).

-- run commands are compose of semicolon

-- have some build-in commands (cd, pwd, history, exit)

-- commands and file's name can auto completion (Tab)

-- press up and down to lookup the historical command

-- press left and right to modify the input

-- Ctrl + L to clear the screen

-- if [ number ]; then command; fi

-- while [ number ]; do command; done

-- more...

You need the library of "readline". Use make.