SMALLSH

Introduction

My own shell written in C which implements a command line interface similar to well-known shells, such as bash.

The program:

1. Prints an interactive input prompt
2. Parses command line input into semantic tokens
3. Implements parameter expansion
   • Shell special parameters $$, $?, and $!
   • Tilde (~) expansion
4. Implements two shell built-in commands: exit and cd
5. Executes non-built-in commands using the the appropriate EXEC(3) function.
6. Implements redirection operators ‘<’ and ‘>’
7. Implements the ‘&’ operator to run commands in the background
8. Implements custom behavior for SIGINT and SIGTSTP signals

Program Functionality

1. Input
2. Word splitting
3. Expansion
4. Parsing
5. Execution
6. Waiting