myshell — Unix-like Shell in C

A lightweight Unix-like shell implemented in C using POSIX system calls.

Overview

This project implements a simple Unix shell capable of executing external commands, handling background/foreground processes, aliases, signal control, and I/O redirection.

The implementation avoids system() and instead manually traverses the PATH environment variable to locate executables using execv().

Features

External Command Execution

• Uses fork() and execv()
• Manual PATH traversal
• Proper stderr error reporting

Job Control

• Foreground execution
• Background execution using &
• fg %pid support
• Safe exit if background jobs exist

Built-in Commands

• alias "<command>" <name>
• unalias <name>
• alias -l
• exit

I/O Redirection

• >
• >>
• <
• 2>
• Combined redirections supported

Signal Handling

• Handles SIGTSTP (Ctrl+Z)
• Prevents shell from being terminated accidentally

Build

gcc -Wall -Wextra -o myshell main.c
./myshell

## Learning Outcomes

Through this project, I gained hands-on experience with:

- Unix process lifecycle management
- Low-level system calls
- File descriptor manipulation
- Signal handling
- Building a command interpreter from scratch

This project reflects my understanding of operating system fundamentals and system-level programming.