mbsync-notify.sh

mbsync-notify.sh

#!/usr/bin/env bash
# This file:
#
#  - Uses mbsync to check your email if you have a connection to the server.
#  - Slows down syncing if you're on battery
#  - Notifies you of new emails
#
#
# Usage:
#
#  LOG_LEVEL=4 ./mbsync-notify.sh -a account
#
#
# Note:
#
#  This script is meant to be run automatically. Either from cron, or launchd.
#
#  This script requires that you place "Host" directly below "IMAPAccount
#  account" in your mbsyncrc-file. Like this:
#
#  IMAPAccount example
#  Host imap.example.tld
#
#  Also, this script can only sync one account at a time. Do not use it to sync
#  all accounts at the same time. If you want to sync several accounts, run the
#  script several times.
#
#  $__skip defines number of automatic syncs to skip. If $__skip is 2, the sync
#  will happen every third time it is automatically run.
#
# The MIT License (MIT)
# Copyright (c) 2017 Dennis Eriksen <https://dnns.no>
#
# Based on offlineimap-notify.sh by John Louis Del Rosario <https://github.com/john2x>
#
# Also
#
# Based on a template by BASH3 Boilerplate v2.3.0
# http://bash3boilerplate.sh/#authors
#
# The MIT License (MIT)
# Copyright (c) 2013 Kevin van Zonneveld and contributors
# You are not obligated to bundle the LICENSE file with your b3bp projects as long
# as you leave these references intact in the header comments of your source files.

# Exit on error. Append "|| true" if you expect an error.
set -o errexit
# Exit on error inside any functions or subshells.
set -o errtrace
# Do not allow use of undefined vars. Use ${VAR:-} to use an undefined VAR
set -o nounset
# Catch the error in case mysqldump fails (but gzip succeeds) in `mysqldump |gzip`
set -o pipefail
# Turn on traces, useful while debugging but commented out by default
# set -o xtrace


if [[ "${BASH_SOURCE[0]}" != "${0}" ]]; then
  __i_am_main_script="0" # false

  if [[ "${__usage+x}" ]]; then
    if [[ "${BASH_SOURCE[1]}" = "${0}" ]]; then
      __i_am_main_script="1" # true
    fi

    __b3bp_external_usage="true"
    __b3bp_tmp_source_idx=1
  fi
else
  __i_am_main_script="1" # true
  [[ "${__usage+x}" ]] && unset -v __usage
  [[ "${__helptext+x}" ]] && unset -v __helptext
fi

# Set magic variables for current file, directory, os, etc.
__dir="$(cd "$(dirname "${BASH_SOURCE[${__b3bp_tmp_source_idx:-0}]}")" && pwd)"
__file="${__dir}/$(basename "${BASH_SOURCE[${__b3bp_tmp_source_idx:-0}]}")"
__base="$(basename "${__file}" .sh)"


# Define the environment variables (and their defaults) that this script depends on
LOG_LEVEL="${LOG_LEVEL:-6}" # 7 = debug -> 0 = emergency
NO_COLOR="${NO_COLOR:-}"    # true = disable color. otherwise autodetected


### Functions
##############################################################################

function __b3bp_log () {
  local log_level="${1}"
  shift

  # shellcheck disable=SC2034
  local color_debug="\x1b[35m"
  # shellcheck disable=SC2034
  local color_info="\x1b[32m"
  # shellcheck disable=SC2034
  local color_notice="\x1b[34m"
  # shellcheck disable=SC2034
  local color_warning="\x1b[33m"
  # shellcheck disable=SC2034
  local color_error="\x1b[31m"
  # shellcheck disable=SC2034
  local color_critical="\x1b[1;31m"
  # shellcheck disable=SC2034
  local color_alert="\x1b[1;33;41m"
  # shellcheck disable=SC2034
  local color_emergency="\x1b[1;4;5;33;41m"

  local colorvar="color_${log_level}"

  local color="${!colorvar:-${color_error}}"
  local color_reset="\x1b[0m"

  if [[ "${NO_COLOR:-}" = "true" ]] || [[ "${TERM:-}" != "xterm"* ]] || [[ ! -t 2 ]]; then
    if [[ "${NO_COLOR:-}" != "false" ]]; then
      # Don't use colors on pipes or non-recognized terminals
      color=""; color_reset=""
    fi
  fi

  # all remaining arguments are to be printed
  local log_line=""

  while IFS=$'\n' read -r log_line; do
    if [[ "${__logfile:-}" ]]; then
      echo -e "$(date -u +"%Y-%m-%d %H:%M:%S UTC") ${color}$(printf "[%9s]" "${log_level}")${color_reset} ${log_line}" | tee -a "${__logfile}"
    else
      echo -e "$(date -u +"%Y-%m-%d %H:%M:%S UTC") ${color}$(printf "[%9s]" "${log_level}")${color_reset} ${log_line}" 1>&2
    fi
  done <<< "${@:-}"
}

function emergency () {                                __b3bp_log emergency "${@}"; exit 1; }
function alert ()     { [[ "${LOG_LEVEL:-0}" -ge 1 ]] && __b3bp_log alert "${@}"; true; }
function critical ()  { [[ "${LOG_LEVEL:-0}" -ge 2 ]] && __b3bp_log critical "${@}"; true; }
function error ()     { [[ "${LOG_LEVEL:-0}" -ge 3 ]] && __b3bp_log error "${@}"; exit 1; }
function warning ()   { [[ "${LOG_LEVEL:-0}" -ge 4 ]] && __b3bp_log warning "${@}"; true; }
function notice ()    { [[ "${LOG_LEVEL:-0}" -ge 5 ]] && __b3bp_log notice "${@}"; true; }
function info ()      { [[ "${LOG_LEVEL:-0}" -ge 6 ]] && __b3bp_log info "${@}"; true; }
function debug ()     { [[ "${LOG_LEVEL:-0}" -ge 7 ]] && __b3bp_log debug "${@}"; true; }

function help () {
  echo "" 1>&2
  echo " ${*}" 1>&2
  echo "" 1>&2
  echo "  ${__usage:-No usage available}" 1>&2
  echo "" 1>&2

  if [[ "${__helptext:-}" ]]; then
    echo " ${__helptext}" 1>&2
    echo "" 1>&2
  fi

  exit 1
}

function clean () {
  sed "s/^\[/\\\[/g" | sed "s/\"/'/g" | sed 's/\!/❕ /g'
}

### Parse commandline options
##############################################################################

# Commandline options. This defines the usage page, and is used to parse cli
# opts & defaults from. The parsing is unforgiving so be precise in your syntax
# - A short option must be preset for every long option; but every short option
#   need not have a long option
# - `--` is respected as the separator between options and arguments
# - We do not bash-expand defaults, so setting '~/app' as a default will not resolve to ${HOME}.
#   you can use bash variables to work around this (so use ${HOME} instead)

# shellcheck disable=SC2015
[[ "${__usage+x}" ]] || read -r -d '' __usage <<-'EOF' || true # exits non-zero when EOF encountered
  -a --account  [arg] Account to sync with mbsync. Required.
  -c --config   [arg] Your mbsyncrc-config. Default="${HOME}/.mbsyncrc"
  -s --skip     [arg] Number of syncs to skip if on battery. Default="2"
  -m --maildir  [arg] Maildir. If you want notifications.
  -t --temp     [arg] Directory for tempfile. Default="/tmp/"
  -l --logfile  [arg] Location of logfile
  -v                  Enable verbose mode, print script as it is executed
  -d --debug          Enables debug mode
  -h --help           This page
  -n --no-color       Disable color output
  -1 --one            Do just one thing
EOF

# shellcheck disable=SC2015
[[ "${__helptext+x}" ]] || read -r -d '' __helptext <<-'EOF' || true # exits non-zero when EOF encountered
  --maildir activates notifications. The maildir needs to be in Maildir-format,
  and your inbox must be found in maildir/INBOX.

  Note that all directories must end in /.
EOF

# Translate usage string -> getopts arguments, and set $arg_<flag> defaults
while read -r __b3bp_tmp_line; do
  if [[ "${__b3bp_tmp_line}" =~ ^- ]]; then
    # fetch single character version of option string
    __b3bp_tmp_opt="${__b3bp_tmp_line%% *}"
    __b3bp_tmp_opt="${__b3bp_tmp_opt:1}"

    # fetch long version if present
    __b3bp_tmp_long_opt=""

    if [[ "${__b3bp_tmp_line}" = *"--"* ]]; then
      __b3bp_tmp_long_opt="${__b3bp_tmp_line#*--}"
      __b3bp_tmp_long_opt="${__b3bp_tmp_long_opt%% *}"
    fi

    # map opt long name to+from opt short name
    printf -v "__b3bp_tmp_opt_long2short_${__b3bp_tmp_long_opt//-/_}" '%s' "${__b3bp_tmp_opt}"
    printf -v "__b3bp_tmp_opt_short2long_${__b3bp_tmp_opt}" '%s' "${__b3bp_tmp_long_opt//-/_}"

    # check if option takes an argument
    if [[ "${__b3bp_tmp_line}" =~ \[.*\] ]]; then
      __b3bp_tmp_opt="${__b3bp_tmp_opt}:" # add : if opt has arg
      __b3bp_tmp_init=""  # it has an arg. init with ""
      printf -v "__b3bp_tmp_has_arg_${__b3bp_tmp_opt:0:1}" '%s' "1"
    elif [[ "${__b3bp_tmp_line}" =~ \{.*\} ]]; then
      __b3bp_tmp_opt="${__b3bp_tmp_opt}:" # add : if opt has arg
      __b3bp_tmp_init=""  # it has an arg. init with ""
      # remember that this option requires an argument
      printf -v "__b3bp_tmp_has_arg_${__b3bp_tmp_opt:0:1}" '%s' "2"
    else
      __b3bp_tmp_init="0" # it's a flag. init with 0
      printf -v "__b3bp_tmp_has_arg_${__b3bp_tmp_opt:0:1}" '%s' "0"
    fi
    __b3bp_tmp_opts="${__b3bp_tmp_opts:-}${__b3bp_tmp_opt}"
  fi

  [[ "${__b3bp_tmp_opt:-}" ]] || continue

  if [[ "${__b3bp_tmp_line}" =~ (^|\.\ *)Default= ]]; then
    # ignore default value if option does not have an argument
    __b3bp_tmp_varname="__b3bp_tmp_has_arg_${__b3bp_tmp_opt:0:1}"

    if [[ "${!__b3bp_tmp_varname}" != "0" ]]; then
      __b3bp_tmp_init="${__b3bp_tmp_line##*Default=}"
      __b3bp_tmp_re='^"(.*)"$'
      if [[ "${__b3bp_tmp_init}" =~ ${__b3bp_tmp_re} ]]; then
        __b3bp_tmp_init="${BASH_REMATCH[1]}"
      else
        __b3bp_tmp_re="^'(.*)'$"
        if [[ "${__b3bp_tmp_init}" =~ ${__b3bp_tmp_re} ]]; then
          __b3bp_tmp_init="${BASH_REMATCH[1]}"
        fi
      fi
    fi
  fi

  if [[ "${__b3bp_tmp_line}" =~ (^|\.\ *)Required\. ]]; then
    # remember that this option requires an argument
    printf -v "__b3bp_tmp_has_arg_${__b3bp_tmp_opt:0:1}" '%s' "2"
  fi

  printf -v "arg_${__b3bp_tmp_opt:0:1}" '%s' "${__b3bp_tmp_init}"
done <<< "${__usage:-}"

# run getopts only if options were specified in __usage
if [[ "${__b3bp_tmp_opts:-}" ]]; then
  # Allow long options like --this
  __b3bp_tmp_opts="${__b3bp_tmp_opts}-:"

  # Reset in case getopts has been used previously in the shell.
  OPTIND=1

  # start parsing command line
  set +o nounset # unexpected arguments will cause unbound variables
                 # to be dereferenced
  # Overwrite $arg_<flag> defaults with the actual CLI options
  while getopts "${__b3bp_tmp_opts}" __b3bp_tmp_opt; do
    [[ "${__b3bp_tmp_opt}" = "?" ]] && help "Invalid use of script: ${*} "

    if [[ "${__b3bp_tmp_opt}" = "-" ]]; then
      # OPTARG is long-option-name or long-option=value
      if [[ "${OPTARG}" =~ .*=.* ]]; then
        # --key=value format
        __b3bp_tmp_long_opt=${OPTARG/=*/}
        # Set opt to the short option corresponding to the long option
        __b3bp_tmp_varname="__b3bp_tmp_opt_long2short_${__b3bp_tmp_long_opt//-/_}"
        printf -v "__b3bp_tmp_opt" '%s' "${!__b3bp_tmp_varname}"
        OPTARG=${OPTARG#*=}
      else
        # --key value format
        # Map long name to short version of option
        __b3bp_tmp_varname="__b3bp_tmp_opt_long2short_${OPTARG//-/_}"
        printf -v "__b3bp_tmp_opt" '%s' "${!__b3bp_tmp_varname}"
        # Only assign OPTARG if option takes an argument
        __b3bp_tmp_varname="__b3bp_tmp_has_arg_${__b3bp_tmp_opt}"
        printf -v "OPTARG" '%s' "${@:OPTIND:${!__b3bp_tmp_varname}}"
        # shift over the argument if argument is expected
        ((OPTIND+=__b3bp_tmp_has_arg_${__b3bp_tmp_opt}))
      fi
      # we have set opt/OPTARG to the short value and the argument as OPTARG if it exists
    fi
    __b3bp_tmp_varname="arg_${__b3bp_tmp_opt:0:1}"
    __b3bp_tmp_default="${!__b3bp_tmp_varname}"

    __b3bp_tmp_value="${OPTARG}"
    if [[ -z "${OPTARG}" ]] && [[ "${__b3bp_tmp_default}" = "0" ]]; then
      __b3bp_tmp_value="1"
    fi

    printf -v "${__b3bp_tmp_varname}" '%s' "${__b3bp_tmp_value}"
    debug "cli arg ${__b3bp_tmp_varname} = (${__b3bp_tmp_default}) -> ${!__b3bp_tmp_varname}"
  done
  set -o nounset # no more unbound variable references expected

  shift $((OPTIND-1))

  if [[ "${1:-}" = "--" ]] ; then
    shift
  fi
fi


### Automatic validation of required option arguments
##############################################################################

for __b3bp_tmp_varname in ${!__b3bp_tmp_has_arg_*}; do
  # validate only options which required an argument
  [[ "${!__b3bp_tmp_varname}" = "2" ]] || continue

  __b3bp_tmp_opt_short="${__b3bp_tmp_varname##*_}"
  __b3bp_tmp_varname="arg_${__b3bp_tmp_opt_short}"
  [[ "${!__b3bp_tmp_varname}" ]] && continue

  __b3bp_tmp_varname="__b3bp_tmp_opt_short2long_${__b3bp_tmp_opt_short}"
  printf -v "__b3bp_tmp_opt_long" '%s' "${!__b3bp_tmp_varname}"
  [[ "${__b3bp_tmp_opt_long:-}" ]] && __b3bp_tmp_opt_long=" (--${__b3bp_tmp_opt_long//_/-})"

  help "Option -${__b3bp_tmp_opt_short}${__b3bp_tmp_opt_long:-} requires an argument"
done


### Cleanup Environment variables
##############################################################################

for __tmp_varname in ${!__b3bp_tmp_*}; do
  unset -v "${__tmp_varname}"
done

unset -v __tmp_varname


### Externally supplied __usage. Nothing else to do here
##############################################################################

if [[ "${__b3bp_external_usage:-}" = "true" ]]; then
  unset -v __b3bp_external_usage
  return
fi


### Signal trapping and backtracing
##############################################################################

#function __b3bp_cleanup_before_exit () {
#  info "Cleaning up. Done"
#  rm "${__tempfile}"
#}
#trap __b3bp_cleanup_before_exit EXIT

# requires `set -o errtrace`
__b3bp_err_report() {
    local error_code
    error_code=${?}
    error "Error in ${__file} in function ${1} on line ${2}"
    exit ${error_code}
}
# Uncomment the following line for always providing an error backtrace
# trap '__b3bp_err_report "${FUNCNAME:-.}" ${LINENO}' ERR


### Command-line argument switches (like -d for debugmode, -h for showing helppage)
##############################################################################

# debug mode
if [[ "${arg_d:?}" = "1" ]]; then
  set -o xtrace
  LOG_LEVEL="7"
  # Enable error backtracing
  trap '__b3bp_err_report "${FUNCNAME:-.}" ${LINENO}' ERR
fi

# verbose mode
if [[ "${arg_v:?}" = "1" ]]; then
  set -o verbose
fi

# no color mode
if [[ "${arg_n:?}" = "1" ]]; then
  NO_COLOR="true"
fi

# help mode
if [[ "${arg_h:?}" = "1" ]]; then
  # Help exists with code 1
  help "Help using ${0}"
fi

# logfile
if [[ "${arg_l:-}" ]]; then
  # check if we have write-permissions to logfile
  touch "${arg_l}" >/dev/null 2>&1 || emergency "You can not write to ${arg_l}"
  __logfile="${arg_l}"
fi

# Account
__account="${arg_a}"

# tempfile
if [[ "${arg_t:-}" ]]; then
  if ! [[ "${arg_t: -1}" = "/" ]]; then
    error 'All directories must end in "/"'
  fi
  # check if we have write-permissions to tempfile
  touch "${arg_t}${__account}" >/dev/null 2>&1 || emergency "You can not write to ${arg_t}"
  __tempfile="${arg_t}${__account}"
  __tempdir="${arg_t}"
fi

# maildir
if [[ "${arg_m:-}" ]]; then
  if ! [[ "${arg_m: -1}" = "/" ]]; then
    error 'All directories must end in "/"'
  elif ! [ -r "${arg_m}" ]; then
    error "You can't read ${arg_m}"
  fi
  __maildir="${arg_m}"
fi

### Validation. Error out if the things required for your script are not present
##############################################################################

[[ "${arg_a:-}" ]]     || help      "You need to specify which account you want to sync."
[[ "${LOG_LEVEL:-}" ]] || emergency "Cannot continue without LOG_LEVEL. "

if ! [ -r "${arg_c}" ]; then
  error "You can not read ${arg_c}. Please make sure you can read the mbsyncrc-file."
else
  __config="${arg_c}"
fi

if ! grep -E "(Channel|Group) ${__account}" "${__config}" >/dev/null 2>&1; then
  error "Could not find channel or group named ${__account} to sync"
fi

__num='^[0-9]+$'
if ! [[ "${arg_s}" =~ ${__num} ]]; then
  error "-s requires a number"
elif [ "${arg_s}" -ge 255 ]; then
  error "Come on."
else
  __skip="${arg_s}"
fi


### Runtime
##############################################################################

# if we're on battery
if pmset -g batt | grep "Battery Power" >/dev/null 2>&1; then

  info "We're on battery. Skipping some syncs."
  # when we're on battery, we're supposed to skip n syncs
  # we use the tempfile to store this.

  if [ -f "${__tempfile}" ]; then
    __skipped=$(cat "${__tempfile}")
    if ! [[ "${__skipped}" =~ ${__num} ]]; then
      notice "Your tempfile does not contain a number. It will be overwritten."
      echo "0" > "${__tempfile}"
      notice "Skipping sync because we're on battery."
      exit 0
    elif [[ "${__skipped}" -lt "${__skip}" ]]; then
      let "__skipped += 1"
      echo "${__skipped}" > "${__tempfile}"
      info "We've now skipped ${__skipped} syncs."
      notice "Skipping sync because we're on battery."
      exit 0
    else
      info "Already skipped ${__skip} syncs. Continuing sync."
      echo "0" > "${__tempfile}"
    fi
  fi
else
  info "On AC. Continuing sync."
fi



# If we've gooten here, we've either skipped the right amount of sync-cycles,
# or we're on AC-power. Let's sync!

notice "Syncing ${__account}..."
mbsync "${__account}"

# if we want notifications
if [[ "${__maildir:-}" ]]; then
  info "Setting up notifications"
  __prevmsgs="${__tempdir}mbsync-notify-${__account}"
  __newmsgs=0
  __sender=''
  __subject=''

  __maildirnew="${__maildir}INBOX/new"

  touch "${__prevmsgs}" >/dev/null 2>&1 || error "You can not write to ${__prevmsgs}"

  # check if the mails weren't already seen/reported before
  # and add them to a temporary list of previously seen/reported mails

  for __file in "${__maildirnew}"/*; do
    if ! [ -f "${__file}" ]; then
      continue
    fi

    __filename=$(basename "${__file}")
    if ! grep -Fxq "${__filename}" "${__prevmsgs}"; then
      debug "Found new email - ${__filename}"
      echo "${__filename}" >> "${__prevmsgs}"
      let "__newmsgs += 1"
      debug "New messages: ${__newmsgs}"
      if [ -z "${__sender}" ]; then
        __sender="$(grep -o '^From: \(.*\)$' ${__file} | sed "s/^From: //g" | clean)"
      fi
      if [ -z "${__subject:-}" ]; then
        __subject="$(grep -o '^Subject: \(.*\)$' ${__file} \
          | sed "s/^Subject: //g" \
          | perl -pe 'use MIME::Words(decode_mimewords); $_=decode_mimewords($_);' \
          | clean)"
      fi
    fi
  done

  if [[ "${__newmsgs}" = 0 ]]; then
    info "No new messages found."
    exit 0
  fi

  info "Found ${__newmsgs} new messages"
  debug '${__sender}'": ${__sender}"
  debug '${__subject}'": ${__subject}"
  if [[ "${__newmsgs}" -gt 1 ]]; then
    __title="${__newmsgs} new messages for ${__account} 📬"
    __subtitle=$(echo -e "${__sender} and others")
  else
    __title="New message for ${__account} ✉️ "
    __subtitle=$(echo -e "${__sender}")
  fi
  __body=$(echo -e "${__subject}")

  info "Sending notification."
  debug "Notification:"
  debug "${__title}"
  debug "${__subtitle}"
  debug "${__body}"
  terminal-notifier -title "${__title}" -subtitle "${__subtitle}" -message "${__body}" -sender 'com.apple.Mail'

fi

info "Done."
exit 0

no.dnns.mbsync-notify-cookie.plist

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
        <key>EnvironmentVariables</key>
        <dict>
                <key>PATH</key>
                <string>/usr/local/bin:/usr/bin:/bin:/usr/sbin:/sbin:/opt/X11/bin:/usr/local/sbin</string>
        </dict>
        <key>Label</key>
        <string>no.dnns.mbsync-notify-cookie</string>
        <key>ProgramArguments</key>
        <array>
                <string>/Users/dennis/bin/mbsync-notify.sh</string>
                <string>-s</string>
                <string>1</string>
                <string>-a</string>
                <string>cookie</string>
                <string>-c</string>
                <string>/Users/dennis/.mbsyncrc</string>
                <string>-t</string>
                <string>/Users/dennis/.cache/mbsync/</string>
                <string>-m</string>
                <string>/Users/dennis/Mail/cookie/</string>
        </array>
        <key>RunAtLoad</key>
        <false/>
        <key>StartInterval</key>
        <integer>300</integer>
</dict>
</plist>