Total free and used memory

memory_usage_report.sh

#!/bin/bash

# Free memory
memory_free=$(vm_stat | awk '/Pages free/{ print $NF }' | sed 's/.$//')
memory_speculative=$(vm_stat | awk '/speculative/{ print $NF }' | sed 's/.$//')
memory_inactive=$(vm_stat | awk '/Pages inactive/{ print $NF }' | sed 's/.$//')

# Used memory
memory_app=$(( $(sysctl -n vm.page_pageable_internal_count) - $(vm_stat | awk '/Pages purgeable/{ print $NF }' | sed 's/.$//') ))
memory_wired=$(vm_stat | awk '/Pages wired/{ print $NF }' | sed 's/.$//')
memory_occupied=$(vm_stat | awk '/Pages occupied/{ print $NF }' | sed 's/.$//')

total_free=$(( ( memory_free + memory_speculative + memory_inactive ) * 4096 / 1048576 ))
total_used=$(( ( memory_app + memory_wired + memory_occupied ) * 4096 / 1048576 ))

echo $total_free MB
echo $total_used MB