lolsh

#!/bin/bash

if [[ -n "$1" ]]; then
	PID=$1
else
	PID=$PPID
fi

PROMPT="$ "
SHELL_DEPTH=1

trap its_a_trap 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31

function its_a_trap()
{
	echo -n ''
#	echo -n "$PROMPT"
}

function new_shell()
{
	let SHELL_DEPTH++
	sleep 0.5
}

function exit_shell()
{
	let SHELL_DEPTH--
	if [[ "$1" == "eof" ]]; then
		echo
	fi

	if [[ $SHELL_DEPTH -le 0 ]]; then
		die ded
	fi
}

function die()
{
	kill -9 $PID 2>/dev/null
	exit 0
}

while :; do
	# Prompt the user
	read -p "$PROMPT" cmd
	status="$?"

	# Strip away any "comments"
	cmd="$(echo $cmd | sed 's/#.*//')"

	if [[ "$cmd" == "exit" ]]; then
		# "Exit" the current "shell" (decrement the shell depth)
		exit_shell
	elif [[ "$status" -eq 1 ]]; then
		# ^D / EOF causes read to exit with a status code of 1
		# Other... things? might cause that as well...?
		# Dunno, I just assume that if $? is 1 then the user hit ^D
		exit_shell eof
	elif [[ "$cmd" == "sh" || "$cmd" == "/bin/sh" ]]; then
		# Increment the shell depth
		new_shell
	elif [[ -n "$cmd" ]]; then
		# Tell the user that the command wasn't found
		arr=($cmd)
		echo "${arr[0]}: command not found"
	fi
done