image_sd_card.sh

#!/usr/bin/env bash
# This script looks for the following environment variables and prompts if they are not present:
# DISK

# Todo: Make script detect the latest version of raspbian.

## No bash script should be considered releasable until it has this! ##
# Exit on use of an uninitialized variable
set -o nounset
# Exit if any statement returns a non-true return value (non-zero).
set -o errexit

VERSION=2013-02-09-wheezy-raspbian
CACHE_DIR=~/.raspbian

doUnmount(){
  if [[ $(uname) == Darwin ]]; then
    for d in $DISK*; do diskutil unmount $d || true; done
  else
    for d in $DISK*; do umount $d || true; done
  fi
}

if [[ ! -f $CACHE_DIR/$VERSION.zip ]]; then
  (
    mkdir -f $CACHE_DIR
    cd $CACHE_DIR
    curl -O http://downloads.raspberrypi.org/images/raspbian/2013-02-09-wheezy-raspbian/2013-02-09-wheezy-raspbian.zip
  )
fi

if [[ $(uname) == Darwin ]]; then
  for d in $(diskutil list | grep dev); do diskutil info $d | grep -E 'Node|Media Name'; echo; done
else
  sudo parted -l | grep -A1 'Model:'
fi
while [[ -z ${DISK:-} ]]; do
  read -p 'which disk? ' DISK
done;

# make sure the unzipped image file gets deleted
trap 'rm $CACHE_DIR/$VERSION.img' EXIT
unzip $CACHE_DIR/$VERSION.zip -d $CACHE_DIR/

doUnmount

if which pv; then
  pv $CACHE_DIR/$VERSION.img | sudo dd bs=1m of=$DISK
else
  time sudo dd bs=1m if=$CACHE_DIR/$VERSION.img of=$DISK
fi

sleep 4; doUnmount