Jekis

#!/bin/bash

function echo_mem_stat () {
    mem_total="$(free | grep 'Mem:' | awk '{print $2}')"
    free_mem="$(free | grep 'Mem:'  | awk '{print $7}')"
    mem_percentage=$(($free_mem * 100 / $mem_total))
    swap_total="$(free | grep 'Swap:' | awk '{print $2}')"
    used_swap="$(free | grep 'Swap:' | awk '{print $3}')"
    swap_percentage=$(($used_swap * 100 / $swap_total))

niw

/*
 * A simple libpng example program
 * http://zarb.org/~gc/html/libpng.html
 *
 * Modified by Yoshimasa Niwa to make it much simpler
 * and support all defined color_type.
 *
 * To build, use the next instruction on OS X.
 * $ brew install libpng
 * $ clang -lz -lpng16 libpng_test.c