fstab-helpers

# generated from util-linux source: libmount/src/utils.c
declare -A pseudofs_types=([anon_inodefs]=1
                           [apparmorfs]=1
                           [autofs]=1
                           [bdev]=1
                           [binder]=1
                           [binfmt_misc]=1
                           [bpf]=1
                           [cgroup]=1
                           [cgroup2]=1
                           [configfs]=1
                           [cpuset]=1
                           [debugfs]=1
                           [devfs]=1
                           [devpts]=1
                           [devtmpfs]=1
                           [dlmfs]=1
                           [dmabuf]=1
                           [drm]=1
                           [efivarfs]=1
                           [fuse]=1
                           [fuse.archivemount]=1
                           [fuse.avfsd]=1
                           [fuse.dumpfs]=1
                           [fuse.encfs]=1
                           [fuse.gvfs-fuse-daemon]=1
                           [fuse.gvfsd-fuse]=1
                           [fuse.lxcfs]=1
                           [fuse.rofiles-fuse]=1
                           [fuse.vmware-vmblock]=1
                           [fuse.xwmfs]=1
                           [fusectl]=1
                           [hugetlbfs]=1
                           [ipathfs]=1
                           [mqueue]=1
                           [nfsd]=1
                           [none]=1
                           [nsfs]=1
                           [overlay]=1
                           [pipefs]=1
                           [proc]=1
                           [pstore]=1
                           [ramfs]=1
                           [resctrl]=1
                           [rootfs]=1
                           [rpc_pipefs]=1
                           [securityfs]=1
                           [selinuxfs]=1
                           [smackfs]=1
                           [sockfs]=1
                           [spufs]=1
                           [sysfs]=1
                           [tmpfs]=1
                           [tracefs]=1
                           [vboxsf]=1
                           [virtiofs]=1)

# generated from: pkgfile -vbr '/fsck\..+' | awk -F. '{ print $NF }' | sort
declare -A fsck_types=([btrfs]=0    # btrfs doesn't need a regular fsck utility
                       [cramfs]=1
                       [erofs]=1
                       [exfat]=1
                       [ext2]=1
                       [ext3]=1
                       [ext4]=1
                       [f2fs]=1
                       [fat]=1
                       [jfs]=1
                       [minix]=1
                       [msdos]=1
                       [reiserfs]=1
                       [vfat]=1
                       [xfs]=1)

# shellcheck disable=SC2059 # $1 and $2 can contain the printf modifiers
out() { printf "$1 $2\n" "${@:3}"; }
error() { out "==> ERROR:" "$@"; } >&2
die() { error "$@"; exit 1; }

try_cast() (
  _=$(( $1#$2 ))
) 2>/dev/null

valid_number_of_base() {
  local base=$1 len=${#2} i=

  for (( i = 0; i < len; i++ )); do
    try_cast "$base" "${2:i:1}" || return 1
  done

  return 0
}

mangle() {
  local i= chr= out=
  local {a..f}= {A..F}=

  for (( i = 0; i < ${#1}; i++ )); do
    chr=${1:i:1}
    case $chr in
      [[:space:]\\])
        printf -v chr '%03o' "'$chr"
        out+=\\
        ;;
    esac
    out+=$chr
  done

  printf '%s' "$out"
}

unmangle() {
  local i= chr= out= len=$(( ${#1} - 4 ))
  local {a..f}= {A..F}=

  for (( i = 0; i < len; i++ )); do
    chr=${1:i:1}
    case $chr in
      \\)
        if valid_number_of_base 8 "${1:i+1:3}" ||
            valid_number_of_base 16 "${1:i+1:3}"; then
          printf -v chr '%b' "${1:i:4}"
          (( i += 3 ))
        fi
        ;;
    esac
    out+=$chr
  done

  printf '%s' "$out${1:i}"
}

optstring_match_option() {
  local candidate pat patterns

  IFS=, read -ra patterns <<<"$1"
  for pat in "${patterns[@]}"; do
    if [[ $pat = *=* ]]; then
      # "key=val" will only ever match "key=val"
      candidate=$2
    else
      # "key" will match "key", but also "key=anyval"
      candidate=${2%%=*}
    fi

    [[ $pat = "$candidate" ]] && return 0
  done

  return 1
}

optstring_remove_option() {
  local o options_ remove=$2 IFS=,

  read -ra options_ <<<"${!1}"

  for o in "${!options_[@]}"; do
    optstring_match_option "$remove" "${options_[o]}" && unset 'options_[o]'
  done

  declare -g "$1=${options_[*]}"
}

optstring_normalize() {
  local o options_ norm IFS=,

  read -ra options_ <<<"${!1}"

  # remove empty fields
  for o in "${options_[@]}"; do
    [[ $o ]] && norm+=("$o")
  done

  # avoid empty strings, reset to "defaults"
  declare -g "$1=${norm[*]:-defaults}"
}

optstring_append_option() {
  if ! optstring_has_option "$1" "$2"; then
    declare -g "$1=${!1},$2"
  fi

  optstring_normalize "$1"
}

optstring_prepend_option() {
  local options_=$1

  if ! optstring_has_option "$1" "$2"; then
    declare -g "$1=$2,${!1}"
  fi

  optstring_normalize "$1"
}

optstring_get_option() {
  local _opts o

  IFS=, read -ra _opts <<<"${!1}"
  for o in "${_opts[@]}"; do
    if optstring_match_option "$2" "$o"; then
      declare -g "$o"
      return 0
    fi
  done

  return 1
}

optstring_has_option() {
  local "${2%%=*}"

  optstring_get_option "$1" "$2"
}

dm_name_for_devnode() {
  read dm_name <"/sys/class/block/${1#/dev/}/dm/name"
  if [[ $dm_name ]]; then
    printf '/dev/mapper/%s' "$dm_name"
  else
    # don't leave the caller hanging, just print the original name
    # along with the failure.
    error 'Failed to resolve device mapper name for: %s' "$1"
  fi
}

fstype_is_pseudofs() {
  (( pseudofs_types["$1"] ))
}

fstype_has_fsck() {
  (( fsck_types["$1"] ))
}