RishShell README

Introduction

RishShell is a custom shell developed by Rishabh Khanna using the C programming language. This shell provides a command-line interface with various implemented commands, allowing users to navigate directories, manage processes, and execute commands efficiently.

How to Run the Shell

To run RishShell, follow these steps:

1. Run make in the RishShell directory.
2. Execute ./RishShell to start the shell.
3. Type "quit," "bye," or "exit" to exit the shell.

Display

Upon execution, the shell prompt takes the form: <username@system_name:curr_dir>. The home directory is represented by "~".

Implemented Commands

1. cd [directory path]

• Changes the current working directory.
• Usage:
  • cd [directory path]: Change to the specified directory.
  • cd or cd ~: Change to the home directory.
  • cd -: Change to the previous working directory.

2. pwd

• Prints the absolute path to the current working directory.

3. echo [string]

• Prints the given string after removing extra white spaces.

4. ls [flags] [directory path]

• Lists files in alphabetical order.
• Flags:
  • -l: Displays extra information regarding files.
  • -a: Displays hidden files.
  • -al or -la: Displays extra information for all files, including hidden ones.

5. repeat

• Executes a given instruction multiple times.
• Usage: repeat [num] [command]

6. pinfo [pid]

• Prints information about a process.
• Usage: pinfo or pinfo [pid]

7. jobs

• Prints information about running and/or stopped background processes.

8. history [number of commands]

• Displays recently executed commands.
• Usage: history or history [num]

9. quit

• Exits the shell.
• Also exits on "bye" and "exit" commands or by pressing Ctrl+D.

Foreground and Background Processes

• Foreground: Handles foreground processes using execvp.
• Background: Handles background processes using execvp and prints information when terminated.

Additional Features

• Supports ';' separated commands.
• Handles extra white spaces in commands.

Files and Implementation

• customCd.c and customCd.h: Implement the cd command.
• customPwd.c and customPwd.h: Implement the pwd command.
• customEcho.c and customEcho.h: Implement the echo command.
• customLs.c and customLs.h: Implement the ls command.
• customRepeat.c and customRepeat.h: Implement the repeat command.
• customPinfo.c and customPinfo.h: Implement the pinfo command.
• jobs.c and jobs.h: Implement the jobs command.
• customHistory.c and customHistory.h: Implement the history command.
• sysCommands.c and sysCommands.h: Implement foreground and background process handling.

Notes

• The shell is equipped to execute multiple ';' separated commands.
• Handles extra spaces and tabs in commands.
• Command history is stored in ".RishShell_history" for reference.

Feel free to explore and customize RishShell for your command-line needs!