make-garbage.sh

#!/bin/bash
# Create some randomly-populated files of varying sizes in the given directory,
# up to a maximum summed size.

min=512
max=$((1024 * 1024))
size=$((1024 * 1024 * 1024))
location="$PWD"
sleep_between=0
#count=1024
verbose=0

usage() {
    echo "usage: $0 [OPTIONS] [LOCATION]"
    echo
    echo "The LOCATION positional argument is used to determine where to create"
    echo "these files. Default is the current working directory."
    echo
    echo "options:"
    echo
    echo "--min X           minimum number of bytes per file (default: $min)"
    echo "--max X           maximum number of bytes per file (default: $max)"
    echo "--size X          maximum apparent size allowed of the given location (default: $size)"
    echo "--sleep X         sleep for X seconds between creating each file (default: $sleep_between)"
    #echo "--count X         maximum number of files allowed in the location (default: $count)"
    echo "-v,--verbose      verbose output"
}

dirsize() {
    local loc
    loc="$1"
    # -x is "one filesystem" flag
    du -b -x -s "$loc" 2>/dev/null | cut -f 1
}

dehumanize() {
    awk '/[0-9]$/{print $1;next};/[gG]/{printf "%u\n", $1*(1024*1024*1024);next;}/[mM]$/{printf "%u\n", $1*(1024*1024);next};/[kK]$/{printf "%u\n", $1*1024;next}' <<< "$1"
}

#filecount() {
#    local loc
#    loc="$1"
#    find "$loc" -type f -maxdepth 1 2>/dev/null | wc -l
#}

percent() {
    local loc
    local size
    loc="$1"
    size="$2"
    printf "%0.2f%%\r" "$(bc -l <<< "($(dirsize "$loc") / $size) * 100")"
}

options=$(getopt -o v -q --long min:,max:,size:,sleep:,verbose -- "$@")

if [[ "$?" != 0 ]]; then
    usage
    exit 1
fi

eval set -- "$options"

while true; do
    case "$1" in
        --max)
            shift
            max="$(dehumanize "$1")"
            ;;
        --min)
            shift
            min="$(dehumanize "$1")"
            ;;
        --size)
            shift
            size="$(dehumanize "$1")"
            ;;
        --sleep)
            shift
            sleep_between="$1"
            ;;
        #--count)
        #    shift
        #    count="$1"
        #    ;;
        --verbose|-v)
            verbose=1
            ;;
        --)
            shift
            [[ ! -z "$1" ]] && location="$1"
            break
            ;;
    esac
    shift
done

# Check args, make sure everything makes sense
if (( "$max" < "$min" )); then
    echo "Max size specified is less than min"
    exit 1
fi

if [[ ! -d "$location" ]]; then
    echo "$location is not a directory"
    exit 1
fi

if (( $verbose )); then
    echo "LOCATION : $location"
    echo "MAX      : $max"
    echo "MIN      : $min"
    echo "SIZE     : $size"
    echo "SLEEP    : $sleep_between"
    #echo "COUNT    : $count"
fi

echo "Creating files in $location allowing the usage on the filesystem to not exceed $size bytes"

while (( "$(dirsize "$location")" < "$size" || "$size" < 0 )); do
    filesize="$(shuf -i "$min"-"$max" -n 1)"
    filename="$(mktemp -p "$location")"
    if (( $verbose )); then
        echo "Creating $filename with $filesize ($(numfmt --to=iec-i --suffix=B $filesize)) random bytes"
    elif (( $size < 0 )); then
        printf "%s\r" "$(du -sh "$location" | cut -f 1)"
    else
        percent "$location" "$size"
    fi
    dd if=/dev/random of="$filename" bs="$filesize" count=1 2>/dev/null
    sleep "$sleep_between"
done