ass2.sh

#!/bin/bash

# Code to disable the CTRL+C way to exit the program.
trap '' 2

# Opening preview of what the user will be greeted upon opening the program.
echo "Welcome to Led_Konfigurator! "
echo "============================ "
echo "Please select an led to configure: "
echo

# *** Task 3 Menu
# Function to return the menu of selected LED.
# To be generated after user selects which LED they will use from the previous menu (mainMenu)
# The expected outcome of this function is that it will display the options that are defined here, and once a user
# selects their option it will complete the task that is defined by the option, it will then call the second case
function secondMenu(){
        echo "===================="
        echo "1) turn on"
        echo "2) turn off"
        echo "3) associate with a system event"
        echo "4) associate with the performance of a process"
        echo "5) stop association with a process' performance"
        echo "6) quit to main menu"
        echo "Please enter a number (1-6) for your choice: "
        echo

	# While loop to stay within the menu after execution of user selected operation 
	while true; do
		secondCase
	done
}

# *** Task 3 Case
# Function for the second case to select what to do with the selected LED.
# The expected outcome of this menu is to complete the option that has been selected by the user.
# This will complete the tasks for the selected LED, which is associated with the function (secondMenu)
function secondCase(){
	# read the user input to use for case statement
        read INPUT
                case $INPUT in
                        1)
				# *** Task 4
				# 1st option: turn ON the LED in that working directory
                                cwd=$(pwd)
                                echo 1 | sudo tee $cwd/brightness > /dev/null
				secondMenu
                                ;;
                        2)
				# *** Task 4
				# 2nd option: turn OFF the LED in that working directory
                                cwd=$(pwd)
                                echo 0 | sudo tee $cwd/brightness > /dev/null
				secondMenu
                                ;;
                        3)
				# 3rd option: Will call the trigger event associated with the selected LED
                                while true; do
	                        	triggerMenu
        			done
	                        ;;
                        4)
				# Work in progress
                                task6
                                ;;
                        5)
				# Task 7, kills the background process that was created by task 6
                                task7
				mainMenu
                                ;;
                        6)
				# 6th option should return user to main menu (mainMenu)
				mainMenu
				;;
                esac
	}

# *** Task 2
# Function that will generate menu from the directories in required folder: Requirement 2
# That required folder being: /sys/class/leds
# The expectation of this menu is that the user can select which LED they would like to use,
# The function will then call the secondMenu for user to decide what they want to do with that selected LED
function mainMenu(){
# Select statement, dynamic so that it will change directories into the selected option, from the generated menu
        cd /sys/class/leds
        COLUMNS=+1

	# PS3 will be the statement that displays what the user should do at the given menu
	PS3="Please enter a number that corresponds to the LED to configure or quit: "

        select files in * Quit;
        # Case statement to select which LED user will be using, which will then print the secondMenu for user.
        do
                case $files in
			#If a user selects the Quit option, the program will exit.
			"Quit")
				echo "Exitting."
				exit
				;;
			# Based on the selection of the user, the program will change directory to the option selected and then print the current directory at the top
                        *)
                                cd "$files"
                                echo
                                printf '%q\n' "${PWD##*/}"
                                secondMenu
                                ;;
                esac
        done


}

# ***Task 5
# Function to associate LED with a system event (Requirement 5)
# Expected result of this function is that it will print the events from the trigger file using cat command
# The function will then read the event that is produced by the menu that the user selects, and echo that
# Command to the trigger file to complete the task selected.
function triggerMenu(){
        echo "Associate Led with a system Event"
        echo "===================================="
        echo "Available events are: "
        echo "----------------"

	PS3="Please select an option (1-33):"

	# Select which will print the events that are allowed by the trigger file from the current working directory
        cwd=$(pwd)
        select event in $(cat $cwd/trigger) "Quit to previous menu";

	# Case statement which will select the event from user input
	# and echo it into the trigger file of the current working directory
	do
                case $event in
			"Quit to previous menu")
				echo "Returning to previous menu."
				secondMenu
				;;
	              	*)
                               	echo $event | sudo tee $cwd/trigger
				triggerMenu
                                ;;
		esac
	done
}

# Task 6
function task6(){
	echo "Associated LED with the performance of a process"
	echo "-----------------------------------"
	echo "Please enter the name of the program to monitor (partial names are ok): "

	read process
	COUNTER=0

	# For loop will print the processes based on the input from the user, defined as process.
	# It will also add a counter to it to track the amount of results
        for results in $(ps -C $process -o comm=); do
        	COUNTER=$(expr $COUNTER + 1)
        done

	# If statements, it will separate whether there are multiple results of the specified process or not.
	if [ $COUNTER -gt 1 ]
	then
		echo
		echo "Name Conflict"
		echo "-------------"
		echo "I have detected a name conflict. Do you want to monitor: "
		for results in $(ps -C $process -o comm=) "Cancel request"; do
               		NEWCOUNTER=$(expr $NEWCOUNTER + 1)
               		echo "${NEWCOUNTER}) ${results}";
	        done

		PS3="Please select an option: "
		# Select loop to return the process name of the input via a user
		select monitor in $results

		do
			# Case statement so that a user can select to either cancel to main menu
			# Or select to monitor cpu or memory
			case $monitor in
				"Cancel request")
					mainMenu
					;;
				*)
					# Save the current directory to return to for after changing directory to executre the background script
					cwd=$(pwd)
					echo "Do you wish to 1) monitor memory or 2) monitor cpu? [enter memory or cpu]: "
                       			read monitor
					# If statement which will execute code depending on the user entering cpu or memory to monitor
		                        if [ $monitor == "cpu" ]
                        		then
						# Change diretory to where the background script is located
						# Run the script in the background 
						# Change back to the stored directory
						# Display the second menu again
						cd /root/ass2/
						exec ./psscript.sh &
						cd ${cwd}
						secondMenu
                       			elif [ $monitor == "memory" ]
                       			then
						# Same documentation for above if the user enters cpu
						cd /root/ass2/
						exec ./psscript.sh &
						cd ${cwd}
						secondMenu
					else
						# If the user enters something other than what is required
               	                		echo "Error please try again."
						secondMenu
					fi
					;;
			esac
		done
	# Else if there is not more than one process with that defined name, execute this following code
	else
		cwd=$(pwd)
		echo "Do you wish to 1) monitor memory or 2) monitor cpu? [enter memory or cpu]: "
		read monitor
		if [ $monitor == "cpu" ]
		then
			# Change directory to the path where script is located
			# Run the script in the background
			# Then switch back to the previously stored directory (that of menu 2) as part of the requirement
			# Finally re-display the options for menu 2.
			# This documentation is the same for if the user enters memory as the monitoring
                	cd /root/ass2/
                        exec ./psscript.sh &
                        cd ${cwd}
                        secondMenu
		elif [ $monitor == "memory" ]
		then
			# Same documentation for above if user enters cpu
                        cd /root/ass2/
                        exec ./psscript.sh &
                        cd ${cwd}
                        secondMenu
		else
			echo "Error please try again."
			secondMenu
		fi
	fi

}

# Function for task 7
# This will kill the background process in which was created via task 6
function task7(){
	pkill -f psscript.sh
}

# This will run the mainMenu, running the program
mainMenu