greyhole_monitor.sh (feat. fancy timer and a callback)

#!/bin/bash

function right-aligned() {
        SPC=$(expr $(tput cols) - ${#1})
        for (( j=1; j<=$SPC; j++ )); do
                echo -n " ";
        done;
        echo -n ${1}
}

function fancy-timer() {
        for (( i=1; i<=$1; i++ )); do
                SEC=$(expr ${1} - $(expr ${i} - 1))
                SECW="second"
                if [ "$SEC" -ne "1" ]; then
                        SECW="${SECW}s"
                fi
                echo -ne "$(right-aligned "${2} ${SEC} ${SECW}")\r"
                sleep 1
        done;
        if [ ! -z "${3}" ]; then
                # Callback
                ${3} ${1} $(date +'%s')
        fi
}

function greyhole_monitor() {
        Z_GHD=$(greyhole -s);
        Z_GHS=$(greyhole -S);
        clear;
        echo -e "${Z_GHD}\\n";
        echo -e "${Z_GHS}\\n";
        df -h /home;
        Z_TIME=${1}
        if [ ! -z "${2}" ]; then
                Z_DATE=$(date +'%s')
                Z_DIFF=$(expr ${Z_DATE} - ${2})
                Z_TIME=$(expr ${Z_TIME} - ${Z_DIFF})
        fi
        fancy-timer ${Z_TIME} "Updated in ${Z_DIFF}s on $(date -d"@${Z_DATE}" +'%I:%M:%S%p [%Y/%m/%d]'), next update in" greyhole_monitor
}
clear
echo "Gathering initial information from Greyhole... This may take a while..."
greyhole_monitor 25 $(date +'%s')