Added 'exit' command implementation.
Added 'dir' command implementation.
Added 'pwd' command implemntation. Modified prompt displaying according to TechTask.
Added 'mkdir' command implementation.
Added 'rm' command implementation.
Fixed crash for launch with arguments.
Замечания исправлены
fixes
error correction 1
Reimplemented input shell system.
First version of calculator
Update Calculator.java

Исправил синтаксис
Showing error message on wrong directory for 'cd' command.
Removed unnecessary semicolon.
Попытка 4, сдача калькулятора, 295 Ивановский
Considering absolute paths case in implemented commands.
Added exit condition on any error occurrence.
Added 'mv' command implementation.
Calculator by Eltyshev. Version 1
Added 'cp' command implementation.