POSIX shell background PID monitor and cleanup

function_pid_monitor.sh

#!/bin/sh

clear

pid1=""
pid2=""

function1() {
    while :; do
        count=$((count + 1))
        printf "\033[17H\033[K"
        printf "\033[2HTask 1: Count = %s \n" "$count"
        sleep 1
    done
    printf "\033[7HFunction 1: Simulating failure!\n"
    exit 1
}

function2() {
    count=0
    while :; do
        count=$((count + 1))
        printf "\033[16H\033[K"
        printf "\033[3HTask 2: Count = %s\n" "$count"
        sleep 2
    done
}

monitor() {
    while :; do
        if ! kill -0 "$pid1" 2>/dev/null; then
            function1 "$pid1" &
            pid1=$!
            printf "\033[16HRestarting Function 1... PID %s \033[K\n" $pid1
        fi

        if ! kill -0 "$pid2" 2>/dev/null; then
            function2 "$pid2" &
            pid2=$!
            printf "\033[17HRestarting Function 2... PID %s \033[K\n" $pid2
        fi

        sleep 3
    done
}

cleanup() {
    printf "\033[6HStopping all processes...\033[K\n"
    [ -n "$pid1" ] && kill "$pid1" 2>/dev/null
    [ -n "$pid2" ] && kill "$pid2" 2>/dev/null
    exit 0
}

trap cleanup INT TERM

printf "Starting Function 1 and Function 2...\n"

# Start function1 and assign its PID
function1 "$pid1" &
pid1=$!
printf "\033[13HPID %s\033[K\n" $pid1

# Ensure function2 gets the correct PID
function2 "$pid2" &
pid2=$!
printf "\033[14HPID %s\033[K\n" $pid2

printf "Main PID %s" "$$"

# Start monitoring
monitor