Simple Shell (dsh)

This project implements a simple Unix shell in C, called dsh. The shell supports executing commands, managing history, redirecting output, and using pipes for inter-process communication.

Features

• Command Execution: You can execute system commands directly from the shell.
• History Management: Executed commands are stored, allowing you to access your command history.
• Output Redirection: Supports redirecting output to files.
• Pipes: Supports using pipes to connect the output of one command to the input of another.

Functionality

Supported Commands

• Execute Commands: Enter the desired command and press Enter to execute it.

  Example:

  ls -l
  

• Exit the Shell: To exit the shell, you can use the exit command.

  Example:

  exit
  

• Set the Path: You can change the command search path using the setpath command.

  Example:

  setpath /usr/local/bin
  

Output Redirection

You can redirect the output of a command to a file using the > symbol for writing and >> for appending.

Examples:

echo "Hello World" > output.txt   # Writes "Hello World" to output.txt
echo "Hello again" >> output.txt   # Appends "Hello again" to output.txt

Pipes

You can use the | symbol to connect the output of one command to the input of another.

Example:

ls -l | grep ".c"   # Displays only files with a .c extension

Installation

To compile and use dsh, ensure you have a C compiler installed. You can use gcc to compile the program.

1. Clone the repository:

   git clone <repository-url>
   cd <repository-directory>

2. Compile the program:

   gcc -o dsh dsh.c -lreadline

3. Run the shell:

   ./dsh

Requirements

• A Unix-like system (Linux or macOS).
• readline library for input management.

Usage Examples

1. Execute a simple command:

   dsh$ ls -l

2. Set a new path:

   dsh$ setpath /usr/local/bin

3. Redirect output to a file:

   dsh$ echo "Hello World" > hello.txt

4. Use a pipe:

   dsh$ ps | grep "bash"

License

This project is licensed under the MIT License. See the LICENSE file for more details.

Acknowledgments

• Thanks to the C developer community for support and resources.