#!/bin/sh

meminfo=$(awk '
/^MemTotal:/ {Total=$2*1024}
/^MemAvailable:/ {Available=$2*1024}
/^MemFree:/ {Free=$2*1024}
/^Buffers:/ {Buffers=$2*1024}
/^Cached:/ {Cached=$2*1024}
/^SReclaimable:/ {SReclaimable=$2*1024}
/^Shmem:/ {Shmem=$2*1024}
END {
print Total ":" Available ":" Free ":" Buffers ":" Cached ":" SReclaimable ":" Shmem}' /proc/meminfo)

echo "$meminfo" |
    while IFS=: read -r t a f b c sr sh; do
        memfree=$(echo "$a $t" | awk '{printf "%.3f", ($1 / $2) * 100}')
        memused=$(echo "$memfree" | awk '{printf "%.3f", (100 - $1)}')

        # Percentage values
        # TODO: other values, controllable by flags?
        echo "$memfree $memused"
    done