watch-download-progress

#!/bin/bash
set -eu
if [ -z "${1:-}" -o -n "${2:-}" ] ; then
    echo "usage: $0 <poll time in seconds>"
    echo
    echo "Run this is a download directory where googlegargle/listerine is operating."
    echo "Prints status updates and tries to stop listerine in case of dangerously low disk space."
    exit 1
fi
interval=$1

# The following might need tuning for non-GNU df(1)s
df_filter() {
    sed 's/  */\t/g' | cut -f 4
}

case $(df -P . | df_filter | head -n1) in
    Available)
        # Okay, we picked the right column from the output
        ;;
    *)
        echo "Sorry, I don't know how to parse the output of your df command. Please try to fix me..."
        exit 1
        ;;
esac

free_space_threshold_kb=$(( 500 * 1024 ))

size=0
time=0
while true
do
    previous_size=$size
    previous_time=$time
    size=$(du -kc ? | tail -n1 | cut -f1)
    time=$(date +%s)
    echo -n "Have $(( $size / 1024 ))M"
    echo -n " in $(find . -name '*flv' | wc -l) files,"
    kbps=$(( $(( $size - $previous_size )) / $(( $time - $previous_time )) ))
    echo -n " growing at ${kbps}k/s."
    free_space_kb=$(df -Pk . | df_filter | tail -n1)
    echo -n " $(( ${free_space_kb} / 1024 ))M of free space"
    if [ $kbps -gt 0 ]; then 
        echo -n ", will last until $(date -d @$(( $(date +%s) + $free_space_kb / $kbps )))"
    fi
    echo -n .
    if [ -f STOP ]; then
        echo " STOP file exists."
    else
        echo
        if [ $free_space_kb -lt $free_space_threshold_kb ]; then
            echo "Running out of disk space! Creating STOP file to warn listerine."
            touch STOP
        fi
    fi
    sleep $interval
done