osx available memory

osx-available-mem.sh

#!/bin/bash
set -e

vmstat=$(vm_stat)

page_size=$(echo "$vmstat"|grep 'page size'|cut -d ' ' -f 8)
free_pages=$(echo "$vmstat"|awk '/^Pages free/ {print substr($3, 1, length($3)-1)}')
inactive_pages=$(echo "$vmstat"|awk '/^Pages inactive/ {print substr($3, 1, length($3)-1)}')
speculative_pages=$(echo "$vmstat"|awk '/^Pages speculative/ {print substr($3, 1, length($3)-1)}')
file_pages=$(echo "$vmstat"|awk '/^File-backed pages/ {print substr($3, 1, length($3)-1)}')

avail_file_caches=$(($page_size*($free_pages+$file_pages)))
avail_inactive=$(($page_size*($free_pages+$inactive_pages))) # vm_stat already substract available pages from free to display free

echo "AVAIL.MEM. (file caches) $(($avail_file_caches/1024/1024))MB"
echo "AVAIL.MEM. (inactive)    $(($avail_inactive/1024/1024))MB"