SubShell 🐚

A custom Unix shell built from scratch in C, running on Linux/WSL.

Features

• Interactive prompt (REPL loop)
• Execute real Linux commands (ls, pwd, echo, mkdir etc.)
• Built-in cd command
• Argument parsing with strtok()
• Process management with fork(), execvp(), wait()

How to Build & Run

gcc shell.c -o shell
./shell

Usage

myshell> ls
myshell> pwd
myshell> echo Hello World
myshell> cd /home
myshell> exit

What I Learned

• How shells work under the hood
• Linux system calls (fork, exec, wait, chdir)
• Process creation and management
• Input parsing in C

Roadmap

• Pipes support (ls | grep txt)
• I/O Redirection (echo hello > file.txt)
• Command history (arrow keys)
• Custom prompt with current directory
• ~ expansion in paths

Tech Stack

• Language: C
• Environment: Ubuntu 22.04 (WSL2)
• Compiler: GCC 11.4