でかいファイルはどれですか？

du.sh

#!/bin/bash

EXCLUDE_DIRS="--exclude={opt,proc,dev,boot,lost+found}"

usage() {
    prog_name="$(basename "$0")"
    cat << EOF
Usage: $prog_name

Require root privilege
EOF
}

is_root_user() {
    local _id="$(id | cut -d' ' -f1 | grep -oE '[0-9]*')"
    if [[ "$_id" -eq 0 ]]; then
        return 0
    else
        return 1
    fi
}

echo_err() {
    echo "ERROR: $1" 2>&1
}

_du() {
    #echo "ionice -c2 -n7 nice -n 19 du -s /* --exclude=$EXCLUDE_DIRS | sort -k1n"
    #ionice -c2 -n7 nice -n 19 du -s /* "$EXCLUDE_DIRS" | sort -k1n
    local _dirs=$(ionice -c2 -n7 nice -n19 du -s /* --exclude={opt,proc,lost+found,dev,boot} | sort -k1n | tail -n 3)
    IFS_BAK="$IFS"
    IFS=$'\n'
    for _dir in ${_dirs[*]}; do
        echo "$_dir"
        local next_dir=$(echo "$_dir" | cut -d$'\t' -f2)
        #echo "$next_dir"
        ionice -c2 -n7 nice -n19 du -s ${next_dir}/* | sort -k1n | tail -n3
        echo
    done
}

restore_ifs_on_exit() {
    if [[ -n "$IFS_BAK" ]]; then
        IFS="$IFS_BAK"
    fi
}

trap restore_ifs_on_exit EXIT

is_root_user
if [[ "$?" -ne 0 ]]; then
    echo_err "Require root privilege"
    exit 1
fi

_du