Mav Shell

Operating System/Assignment-1: Created by Dr. Trevor Bakker

Description

A shell program - Mav shell (msh), similar to bourne shell (bash), c-shell (csh), or korn shell (ksh) with basic functionalities. It accepts the command, navigates through the file system, and executes those commands.

Functionality

• Shell supports any command in /bin,/usr/bin/,/usr/local/bin/, and the current working directory. Parameters may also be combined. Example: ps -aef or ps -a -e -f.
• Supports the showpids command to list the PIDS of the last 15 process spwaned by the shell.
• Supports the history command to list the last 15 commands entered by the user.
• Executes any command from history. Typing !n, where n is a number between 1 and 15 will result in re-running the nth command in shell.

Files Included

• msh.c - Main source code which executes the main program (Mav Shell).
• fork.c- Code that demonstrates the basic concept used in the main source code.
• zombie.c - Code that demonstrates the possible error that might occur while executing fork function.

Things I Learned

• Shell commands and functionalities in UNIX systems.
• Use of fork to handle multiple processes at a time.

Acknowledgements

Dr. Trevor Bakker for providing small stub programs to get started and his guidance throughout the assignment.