#!/bin/bash
	echo "-----------------------------------"
	echo "Administration options of SlackIUL"
	echo "1. Channels list"
	echo "2. Add channel"
	echo "3. Remove channel"
	echo "4. Associate user to channel"
	echo "5. Channel users list"
	echo "6. Remove user from channel"
	echo "7. Exit"
	read x
	case $x in
        1)	cat channels.txt ;;
        2)	echo "Say the channel to add:"
			read channel_add
				if [ grep -q $channel_add 'channels.txt' == 0 ]; then
					echo "Channel already exists"
				else
			                echo "$channel_add" >> "channels.txt"
			  fi ;;
	3)	echo "Say channel to remove:"
			read channel_remove
				if [ grep -q $channel_remove 'channels.txt' == 0 ]; then
					echo "$channel_remove" << "channels.txt"
				else
			                echo "The channel you want to remove, does't exist."
			  fi ;;
  4)	
	5)	echo "Say the channel from wich to list users:"
			read channel
				if [ cat registrations.txt | grep $channel ]; then
					cat registrations.txt | grep $channel | cut -d ' ' -f3
				else 
					echo "The channel doesn't exist!"
				fi ;;
	6)	echo "Say the channel:"
			read channel
		echo "Say the user to remove:"
			read user
				if [ cat registrations.txt | grep $user | grep $channel ]; then
					line=$(cat -n registrations.txt | grep $user | grep $channel)
					echo "$line" << "registrations.txt"
		  fi;;			
	7)	echo "Till next time :)" ;;
	*)	echo "Invalid option"
			x=0;;
	esac
done