A bash scrip to get your Gravatar and save it as an image and a favicon.

update_avatar.sh

#!/bin/bash

# This script downloads a gravatar image associated with EMAIL and saves it at 
# AVATAR_OUTPUT_PATH then creates a favicon icon and saves it at
# FAVICON_OUTPUT_PATH.

EMAIL="[email protected]"
AVATAR_OUTPUT_PATH="static/img/avatar.png"
FAVICON_OUTPUT_PATH="static/favicon.ico"

# https://en.gravatar.com/site/implement/hash/
function email_to_hash {
    echo -n $1 | tr '[A-Z]' '[a-z]' | md5
}

# Stop on error.
set -e

email_hash=$(email_to_hash $EMAIL)

# https://en.gravatar.com/site/implement/images/
wget http://www.gravatar.com/avatar/$email_hash?size=512 -O $AVATAR_OUTPUT_PATH

# http://www.imagemagick.org/Usage/thumbnails/#favicon
convert $AVATAR_OUTPUT_PATH -bordercolor white -border 0 \
    \( -clone 0 -resize 16x16 \) \
    \( -clone 0 -resize 32x32 \) \
    \( -clone 0 -resize 48x48 \) \
    \( -clone 0 -resize 64x64 \) \
    -delete 0 -alpha off -colors 256 $FAVICON_OUTPUT_PATH