Simple Shell Program

This is a simple shell program written in C that provides basic functionality similar to bash. It supports executing commands, changing directories, handling signals, and managing background processes.

Features

• Execute shell commands
• Change current working directory
• Handle signals (SIGINT and SIGTSTP)
• Redirect input and output
• Run processes in foreground and background
• Expand $$ to process id

Usage

To use this shell program, simply compile the shell.c file using a C compiler:

gcc --std=gnu99 -g smallsh.c -o smallsh

The run:

./shell

Once the shell is running, you can enter commands just like you would in a regular shell environment. Some example commands include:

• ls - List files in the current directory
• cd <directory> - Change the current directory
• echo <message> - Print a message to the console
• exit - exit the shell

Additional Notes

• When running a command, you can use & at the end to run it in the background
• Press Ctrl + Z to toggle foreground-only mode. In this mode, the shell will ignore & for background processes
• The shell provides feedback on the termination status of background processes