Save raspberry state as a compressed img file

rasp-backup

#!/usr/bin/env sh

# Sample of use:
#
# rasp-backup /dev/sdc

set -eu
IMG_FILE=rasp.$(date +%Y%m%d.%s).img.gz
GZIP_BIN="$(which pigz)" # tries for multithread gzip
test -z "${GZIP_BIN}" && {
    GZIP_BIN=gzip
}

trap cleanup 2 3 6 15

cleanup() {
  rm -rv "${IMG_FILE}"
  exit 1
}

main() {
    export LANG=en_US
    echo "Creating backup: ${IMG_FILE}"
    dd bs=4M status=progress if="${1}" | "${GZIP_BIN}" > "${IMG_FILE}" || {
        cleanup
    }
}

main "$@"