MacOS SD card backup and restore

sd-backup.sh

#!/bin/bash -e

# simple script to automate backup of SD cards to a file on disk
# only works on Mac OS at this time.

if [ -z "$1" ]; then
    echo "Specify an img name to save to"
    exit
fi

echo Will output data to:
echo $1

diskUtil list

echo "Enter disk number, i.e. the X in /dev/diskX"
read n

echo "Enter the number of 1M blocks"
read count

echo "unmounting"
diskUtil unmountDisk /dev/disk$n

echo "copying (this will take a while)"
dd bs=1m if=/dev/rdisk$n of=$1 count=$count

echo "ejecting"
sleep 2
diskUtil eject /dev/disk$n

echo "done"

sd-flash.sh

#!/bin/bash -e

# simple script to automate flashing an img file to an SD card
# only works on Mac OS at this time.

if [ -z "$1" ]; then
    echo "Specify an img file name on the command line"
    exit
fi

echo Will use iso:
ls $1

diskUtil list

echo "Enter disk number, i.e. the X in /dev/diskX"
read n

echo "unmounting"
diskUtil unmountDisk /dev/disk$n

echo "copying (this will take a while)"
dd bs=1m if=$1 of=/dev/rdisk$n

echo "ejecting"
sleep 2
diskUtil eject /dev/disk$n

echo "done"