Dump/Restore Raspberry Pi SD card image on OS X terminal

raspi-util-functions.sh

# subset of functions.sh from https://github.com/drewlustro/dotfiles
# put in your .bash_profile or .zshrc

function toolbelt-raspi-image-dump() {
    local now=$(date +"%Y-%m-%d__%H-%M-%S");
    local host=${2:="raspi"};
    local diskNumber=${1:--1}
    local bs="1M"
    local cmd="sudo dd if=/dev/rdisk$1 bs=$bs | gzip > ~/Desktop/$host-$now.pi.gz"
    local usage="Usage: $0 [sdCardDiskN] [hostname='raspi']"
    if [ $# -eq 0 ]; then
        echo $usage;
        return 1;
    elif $(diskutil list disk$diskNumber | grep -iq Apple); then
        echo "Warning: Apple filesystem detected on disk $1. This is probably your boot disk or external HDD, dummy. Format to FAT32.";
        return 1;
    fi;

    echo "Will run  '$cmd'";
    echo -n "Are you sure? (y/N): "
    local answer;
    answer=$(bash -c "read -n 1 c; echo \$c");
    if echo "$answer" | grep -iq "^y"; then
        echo "\n\nDumping card $diskNumber..."
        eval $cmd;
        if [[ $? -eq 0 ]]; then
            echo "Success.";
            return 0;
        else
            echo "[error] Dump failed."
            return 1;
        fi
    fi

    echo "\nAborted.";
    return 1;
}

function toolbelt-raspi-image-restore() {
    local diskNumber=${1:--1}
    local bs="1M"
    local cmd="gzip -dc $2 | sudo dd of=/dev/rdisk$1 bs=$bs"
    local usage="Usage: $0 [targetDiskN] [compressedImageFile]"
    if [[ $# -lt 2 ]]; then
        echo $usage;
        return 1;
    elif $(diskutil list disk$diskNumber | grep -iq Apple); then
        echo "Warning: Apple filesystem detected on disk $1. This is probably your boot disk or external HDD, dummy. Format to FAT32.";
        return 1;
    fi;

    echo "Will run  '$cmd'";
    echo -n "Are you sure? (y/N): "
    local answer;
    answer=$(bash -c "read -n 1 c; echo \$c");
    if echo "$answer" | grep -iq "^y"; then
        echo "\n\nRestoring card $(basename $2) to disk $diskNumber..."
        sudo diskutil unmountDisk /dev/disk$diskNumber;
        eval $cmd;
        if [[ $? -eq 0 ]]; then
            echo "Success.";
            return 0;
        else
            echo "[error] Restore failed."
            return 1;
        fi
    fi

    echo "\nAborted.";
    return 1;
}