Interactive C Shell

This project is an implementation of an interactive shell in C, developed as part of an Operating System course. The shell supports various commands and functionalities typical of Unix-like shells.

Features Implemented

Basic System Calls

1. Display Requirement

   • Displays a shell prompt <Username@SystemName:~> showing the current directory.

2. warp

   • Changes the current directory.
   • Supports symbols like ~, ., .., and -.
   • Handles both absolute and relative paths.

3. peek

   • Lists files and directories in a specified directory.
   • Supports flags -a (all files) and -l (detailed info).
   • Handles symbols like ~, ., .., and -.

4. pastevents

   • Stores and retrieves the 15 most recent commands.
   • Supports executing past commands by index.

5. System commands

   • Executes other system commands (e.g., emacs, gedit) in foreground and background processes.

6. proclore

   • Displays information about processes spawned by the shell.

7. seek

   • Searches for files/directories in a target directory.
   • Supports flags -d, -f, and -e.

8. I/O Redirection

   • Supports redirection operators >, >>, and <.

9. Pipes

   • Supports piping multiple commands together.

10. activities

    • Lists processes spawned by the shell.

11. Signals

    • Sends signals to processes (ping command).
    • Handles Ctrl-C, Ctrl-D, and Ctrl-Z signals.

12. fg and bg

    • Brings background processes to foreground (fg).
    • Resumes stopped background processes (bg).

13. Neonate

    • Prints the PID of the most recently created process at intervals until 'x' is pressed.

Networking

14. iMan
    • Fetches man pages from http://man.he.net/ using sockets.
    • Displays basic command information.

Usage

Compilation

Compile the shell using the provided Makefile.

Commands

Use the implemented commands as described in the specifications document.

Additional Notes

• The shell handles both interactive and batch modes.
• Error handling is implemented for various scenarios (e.g., file not found, permission denied).
• Memory management practices are followed to prevent memory leaks.

Credits

This project was developed as part of the Operating System course.