Alarm dialog reminder

#!/bin/bash -

# vim: set tabstop=8 softtabstop=4 shiftwidth=4 smarttab noexpandtab:

${DEBUG}

#========================================================================
#          FILE:  filename
#
#         USAGE:  filename [-h|--help][-V|--version]|[-l|--list]
#                 -l
#                 --list    list alarms
#         -h
#         --help    display program help and exit
#
#         -u
#         --usage   display a usage message and exit
#
#         -V
#         --version display the program version number and exit
#         -x        display debugging information
#
#   DESCRIPTION:  This template is a starting point for creating full-
#         featured shell scripts.
#
#       OPTIONS:  --help, --version
#  REQUIREMENTS:  ---
#          BUGS:  ---
#         NOTES:  ---
#        AUTHOR:  Scott Bicknell (SB), [email protected]
#       COMPANY:
#       VERSION:  1.0
#       CREATED:
#      REVISION:  ---
#
# Copyright 2010 Scott Bicknell, sbicknel (at) gmail dot com
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.
#========================================================================


PROGNAME="${0##*/}"
VERSION='1.0'
PATH="${HOME}/bin:/sbin:/bin:/usr/bin:/usr/local/bin"

# honor the user's editor preference
if [[ -n $EDITOR ]]; then
    editor=$EDITOR
elif [[ -n $VISUAL ]]; then
    editor=$VISUAL
else
    editor=/usr/bin/vi
fi

umask 077

# -----------------------------------------------------------------------
# Display error messages on standard error.
# -----------------------------------------------------------------------
error () {
    printf '%s: %s\n' $PROGNAME "$@"
} >&2


# -----------------------------------------------------------------------
# Display messages on standard output.
# -----------------------------------------------------------------------
message () {
    printf '%s: %s\n' $PROGNAME "$@"
}


# -----------------------------------------------------------------------
# Remove temporary files. Add additional file names, if necessary.
# -----------------------------------------------------------------------
clean_up () {
    rm -f ${TEMP_DIR}/${PROGNAME}.$$.*
}


# -----------------------------------------------------------------------
# toggle write permission on or off. If turning them on, only give them
# to the owner. If turning them off, turn them off for everyone. This
# function operates on a list of files or folders.
# -----------------------------------------------------------------------
toggleWritePermissions () {
    for f in $@; do
    owp=$(stat --printf='%A' $f) # owner's write permissions
    owp=${owp:2:1}
    case $owp in
        -)
        chmod u+w $f
        ;;

        w)
        chmod a-w $f
        ;;
    esac
    done
}


# -----------------------------------------------------------------------
# Function for exit due to fatal program error
#   Accepts 1 argument:
#       string containing descriptive error message
# -----------------------------------------------------------------------
error_exit () {
    error "${1:-'Unknown Error'}"
    clean_up
    exit 1
}


# -----------------------------------------------------------------------
# Function to handle termination signals
#   Accepts 1 argument:
#       signal_spec
# -----------------------------------------------------------------------
signal_exit () {
    case $1 in

    INT)
        error_exit 'Program aborted by user'
        ;;

    TERM)
        error_exit 'Program terminated'
        ;;

    *)
        error_exit 'Terminating on unknown signal'
        ;;

    esac
}

trap 'signal_exit TERM' TERM HUP QUIT PIPE
trap 'signal_exit INT'  INT


# -----------------------------------------------------------------------
# Function called for a graceful exit
#   No arguments
# -----------------------------------------------------------------------
graceful_exit () {
    clean_up
    exit
}


# -----------------------------------------------------------------------
# Function to create temporary files
#   optional number of files to create--default is one
#   returns an array ($TEMP_FILE) containing temporary file names
# -----------------------------------------------------------------------
make_temp_files () {

    declare fnum=${1:-1} # number of temporary files to create

    # Use user's local tmp directory if it exists
    if [[ -d ~/tmp ]]; then
    TEMP_DIR=~/tmp
    else
    TEMP_DIR=/tmp
    fi

    # Temp files for this script, using paranoid method of creation to
    # insure that file names are not predictable. This is for security to
    # avoid "tmp race" attacks.
    for (( n=0; n<$fnum; n++ )); do
    TEMP_FILE[$n]=$(mktemp -q "${TEMP_DIR}/${PROGNAME}.$$.XXXXXX")
    if [[ "${TEMP_FILE[$n]}" = '' ]]; then
        error_exit 'cannot create temp file!'
    fi
    done
}


# -----------------------------------------------------------------------
# Display a short message about program usage. This is also used by the
# helptext function to display part of its help text.
# -----------------------------------------------------------------------
usage () {
    cat <<- EOF

USAGE: $PROGNAME: [-h|--help][-u|--usage][-V|--version][-x]|[-l|--list]
EOF
} >&2


# -----------------------------------------------------------------------
# Display the program version number
# -----------------------------------------------------------------------
version () {
    printf '%s %s\n' $PROGNAME $VERSION
}


# -----------------------------------------------------------------------
# Function to display help message for program
#   No arguments
# -----------------------------------------------------------------------
helptext () {
    local tab=$(printf '\t\t')

    usage
    cat <<- -EOF-


DESCRIPTION:

Create one-time reminders. This program requires either kdialog or
zenity and a valid X \$DISPLAY setting.


Options:

-l, --list      List alarms

-h, --help  Display this help message and exit.
-u, --usage Display a usage message and exit.
-V, --version   Display program version and exit.
-x      Display debugging output when running the program


-EOF-
    version
} >&2


# -----------------------------------------------------------------------
# list pending alarms
# -----------------------------------------------------------------------
listAlarms () {
    # get a list of at jobs
    jobs=( $(atq | awk '{print $1}') )

    # get a list of at jobs containing the text "Alarm"
    for job in ${jobs[@]}; do
    if at -c $job | grep -q 'Alarm'; then
        alarms=( ${alarms[@]} $job )
    fi
    done

    # check for an empty list. Create error message if needed
    if [[ ${#alarms[@]} -eq 0 ]]; then
    alarms[0]='No alarms to list'
    kdialog --msgbox "${alarms[0]}" --title "${PROGNAME^}" 2>/dev/null
    graceful_exit
    fi

    # display the resulting list
    alarmList=$"$(
    for alarm in ${alarms[@]}; do
        atq | grep "^$alarm"
    done | sort
    )"
    case $dialog in
    kdialog)
        kdialog --msgbox "$alarmList" --title "${PROGNAME^}" 2>/dev/null
        ;;

    zenity)
        zenity --info --text="$alarmList" --title="${PROGNAME^}" 2>/dev/null
        ;;

    esac
}

# -----------------------------------------------------------------------
# Verify that the usage function and the helptext function both have
# documentation for each long option. Verify that the header comment
# also has each long option listed.
# -----------------------------------------------------------------------
if [[ "$1" = '--help' ]]; then
    helptext
    graceful_exit
fi
if [[ "$1" = '--version' ]]; then
    version
    graceful_exit
fi
if [[ "$1" = '--usage' ]]; then
    usage
    graceful_exit
fi
if [[ "$1" = '--list' ]]; then
    listAlarms
    graceful_exit
fi

# -----------------------------------------------------------------------
# Verify that the usage function and the helptext function both have
# documentation for each short option. Verify that the header comment
# also has each short option listed in the usage section.
# -----------------------------------------------------------------------

# detect which environment is running and set the dialog program
# appropriately
if [[ "$(pidof ksmserver)" ]]; then
    if which kdialog >/dev/null 2>&1; then
    dialog=kdialog
    elif which zenity >/dev/null 2>&1; then
    dialog=zenity
    else
    error_exit "Please install kdialog"
    fi
elif [[ "$(pidof gnome-session)" ]]; then
    if which zenity >/dev/null 2>&1; then
    dialog=zenity
    elif which kdialog >/dev/null 2>&1; then
    dialog=kdialog
    else
    error_exit "Please install zenity"
    fi
elif [[ "$(pidof xfce-mcs-manager)" ]]; then
    if which zenity >/dev/null 2>&1; then
    dialog=zenity
    elif which kdialog >/dev/null 2>&1; then
    dialog=kdialog
    else
    error_exit "Please install zenity"
    fi
else
    if which kdialog >/dev/null 2>&1; then
    dialog=kdialog
    elif which zenity >/dev/null 2>&1; then
    dialog=zenity
    else
    error_exit "Please install kdialog or zenity"
    fi
fi

while getopts :hluVx opt; do
    case $opt in

    h)
        helptext
        graceful_exit
        ;;

    l)
        listAlarms
        graceful_exit
        ;;

    u)
        usage
        graceful_exit
        ;;

    V)
        version
        graceful_exit
        ;;

    x)  # set debugging output on a per-run basis. The $DEBUG
        # environment variable will enable degugging output at
        # the top of the script.
        set -x
        ;;

    :)  # process missing required parameters
        error_exit "-$OPTARG: required argument missing"
        ;;

    *)  # process unknown options
        error "Unknown option: -$OPTARG"
        usage
        clean_up
        exit 1
        ;;

    esac
done
shift $[ $OPTIND - 1 ]

# to create multiple files, give number as argument to function call. This
# creates an array of file names starting at index 0 ($TEMP_FILE)
make_temp_files 1

case $dialog in

    kdialog)
    time=$(kdialog --inputbox 'Alarm time:' --title "${PROGNAME^}" 2>/dev/null)
    if [[ -z "$time" ]]; then
        graceful_exit
    fi
    case ${time,,} in

        noon)
        time=1200
        ;;

        midnight)
        time=0000
        ;;

    esac
    if ! date --date="$time" >/dev/null; then
        kdialog --msgbox 'Invalid date string' --title "${PROGNAME^}" 2/dev/null
        error_exit 'Invalid date string'
    fi
    alarmTime=$(date --date="$time" '+%-H:%M %b %-d')
    message=$(kdialog --inputbox 'Message:' --title "${PROGNAME^}" 2>/dev/null)
    if [[ -z "$message" ]]; then
        graceful_exit
    fi
    at $alarmTime <<EOF
    export DISPLAY=$DISPLAY
    kdialog --msgbox "$message" --title "${PROGNAME^}" 2>/dev/null
EOF
    kdialog --msgbox "Alarm scheduled for: $alarmTime" --title "${PROGNAME^}" 2>/dev/null
    ;;

    zenity)
    time=$(zenity --entry --text='Alarm time:' --title=${PROGNAME^} 2>/dev/null)
    if [[ -z "$time" ]]; then
        graceful_exit
    fi
    case ${time,,} in

        noon)
        time=1200
        ;;

        midnight)
        time=0000
        ;;

    esac
    if ! date --date="$time" >/dev/null; then
        zenity --info --text='Invalid date string' --title=${PROGNAME^} 2>/dev/null
        error_exit 'Invalid date string'
    fi
    alarmTime=$(date --date="$time" '+%-H:%M %b %-d')
    message=$(zenity --entry --text="Message:" --title=${PROGNAME^} 2>/dev/null)
    if [[ -z "$message" ]]; then
        graceful_exit
    fi
    at $alarmTime <<EOF
    export DISPLAY=$DISPLAY
    zenity --info --text="$message" --title=${PROGNAME^} 2>/dev/null
EOF
    zenity --info --text="Alarm scheduled for: $alarmTime" --title=${PROGNAME^} 2>/dev/null
    ;;

    *)
    error_exit 'no dialog utility found'
    ;;

esac

graceful_exit