write_tf_card.sh

#!/usr/bin/env bash

IMAGES="images"

PATTERN_RASPBERRY_PI_OS='\.\/images\/([0-9]{4}-[0-9]{2}-[0-9]{2})-(raspios)-([^-]*?)-(armhf)(-(full|lite)){0,1}\.zip'
PATTERN_UBUNTU='\.\/images\/ubuntu-[0-9.]*?-(preinstalled)-(desktop|server)-(arm64|armhf)\+raspi\.img\.xz'
PATTERN_OPENWRT='\.\/images\/openwrt-[0-9.]+-bcm27xx-bcm27[0-9]{2}-rpi(-[0-9])?-squashfs-factory\.img\.gz'

declare -A SUPPORT_OS

SUPPORT_OS=(
  [Raspberry Pi OS]=$PATTERN_RASPBERRY_PI_OS
  [Ubuntu]=$PATTERN_UBUNTU
  [OpenWrt]=$PATTERN_OPENWRT
)

TF_CARD=""

OS_IMAGES=()
OS_IMAGE=""

# ------------------------------------------------------------------------------
# functions
# ------------------------------------------------------------------------------

function umount_tf_card() {  # accept one argument about a mount point
  mount_points=()
  while IFS='' read -r line; do
    mount_points+=("$line")
  done < <(lsblk --noheadings --list "$1" | awk '{if (NF==7) {print $7}}')

  for mount_point in "${mount_points[@]}"; do
    umount "$mount_point"
    printf "Umount the mount point %s\n" "$mount_point"
  done

  printf "\n"
}

function get_tf_card() {  # get the tf card to write the image
  # read all usb scsi devices

  tf_cards=()
  while IFS='' read -r line; do
    tf_cards+=("$line")
  done < <(lsblk --noheadings --scsi | awk '/(SD_MMC).*(usb)/{print "/dev/" $1}')

  # echo all usb scsi devices information

  printf "There are %s USB devices on the system now:\n\n" ${#tf_cards[@]}

  lsblk "${tf_cards[@]}"

  printf "\n"

  # select the tf card to write the image

  PS3="Select the tf card to write the image: "

  select tf_card in "${tf_cards[@]}"; do
    TF_CARD=$tf_card
    break
  done

  umount_tf_card "$TF_CARD"
}

function get_images() {  # accept one argument about a regular expression of image name
  while IFS='' read -r line; do
    OS_IMAGES+=("$line")
  done < <(find ./$IMAGES -maxdepth 1 -type f -regextype posix-extended -regex "$1")
}

function get_image() {  # select a image
  PS3="Select OS to write the tf card: "

  select OS in "${!SUPPORT_OS[@]}"; do
    get_images "${SUPPORT_OS[$OS]}"
    break
  done

  PS3="Select the image to write the tf card: "

  select image in "${OS_IMAGES[@]}"; do
    OS_IMAGE="$image"
    break
  done
}

function write_image() {  # write the image to the tf card
  echo "$1"
  case "${1##*.}" in

    "zip")
      FILESIZE=$(unzip -l "$1" | awk '/\.img/ {print $1}')
      # sudo unzip -p "$1" | pv --size "$FILESIZE" | dd of="$TF_CARD" bs=4M
      ;;

    "xz")
      FILESIZE=$(xz -v -l "$1" | awk 'match($0, /Uncompressed size:\s+[0-9,.]+\sMiB\s\(([0-9,]+)\sB\)/, m) {gsub(",", "", m[1])} {print m[1]}')
      xzcat "$1" | pv --size "$(($FILESIZE / 1024 / 1024))M" | dd of="$TF_CARD" bs=4M
      ;;

    "gz")
      FILESIZE=$(gzip --list "$1" | awk 'FNR == 2 {print $2}')
      gzip --decompress --keep --stdout "$1" | pv --size "$(($FILESIZE / 1024 / 1024))M" | dd of="$TF_CARD" bs=4M
      ;;

  esac
}

# ------------------------------------------------------------------------------
# main
# ------------------------------------------------------------------------------

function main() {
  get_tf_card
  get_image
  write_image "$OS_IMAGE"
}

main