A simple script to print the size of Redis keys via scan

redis_key_sizes.sh

#!/bin/bash

# This script prints out all of your Redis keys and their size in a human readable format
# Inspired by https://gist.github.com/epicserve/5699837
# Copyright 2015 amyangfei
# License: http://www.apache.org/licenses/LICENSE-2.0

human_size() {
    awk -v sum="$1" ' BEGIN {hum[1024^3]="Gb"; hum[1024^2]="Mb"; hum[1024]="Kb"; for (x=1024^3; x>=1024; x/=1024) { if (sum>=x) { printf "%.2f %s\n",sum/x,hum[x]; break; } } if (sum<1024) print sum,"bytes"; } '
}

redis_cmd='redis-cli'

handle_key() {
    k=$1
    key_size_byte="$($redis_cmd debug object $k | perl -wpe 's/^.+serializedlength:([\d]+).+$/$1/g') $k"
    # print out key size info with human readable sizes
    size=`echo $key_size_byte | perl -wpe 's/^(\d+).+/$1/g'`; hsize=`human_size "$size"`; key=`echo $key_size_byte | perl -wpe 's/^\d+(.+)/$1/g'`; printf "%-15s%-10s%s\n" "$hsize" "$size" "$k";
}

do_scan() {
    saveIFS="$IFS"
    IFS=$'\n'

    # scan redis keyspace with cursor
    arr=()
    for k in $($redis_cmd scan $1); do
        arr+=("$k")
    done

    # handle scan result
    cursor=${arr[0]}
    arr=("${arr[@]:1}")
    for key in "${arr[@]}"; do
        handle_key $key
    done

    IFS="$saveIFS"

    if [ "$cursor" != "0" ]; then
        do_scan $cursor
    fi
}

do_scan 0