Schedule Linux desktop to automatically join a Zoom meeting

add-zoom-meeting.sh

#!/bin/env bash

# TODO:
# [ ] sanity check for the zoom link.
# [x] check if the meeting is already scheduled.

MINS=$1
HOUR=$2
DATE=$3
MNTH=$4
YEAR="date +%Y"
PAT_CMD="\[ \\\$(date \\\"+\\\\%Y\\\") -eq $($YEAR) \] && export DISPLAY=:0 && xdg-open \\\"$5\\\""
ACT_CMD="[ \$(date \"+\\%Y\") -eq $($YEAR) ] && export DISPLAY=:0 && xdg-open \"$5\""


################################################################################
#                                 Sanity Check
################################################################################

if [ "$#" -ne 5 ]
then
    echo "ERROR: More or less than required parameters are passed."
    echo ""
    echo "Usage: ./add-zoom-meeting.sh <minute> <hour> <date> <month> <link>"
    echo "                               0-59    0-23   1-31   1-12"
    echo "The parameter <minute> should be in normal format (0-59)."
    echo "The parameter <hour> should be in 24-hr format (0-23)."
    echo "The parameter <date> should be in normal format (1-31)."
    echo "The parameter <month> should be in normal format (1-12)."
    echo "The parameter <link> should be in the following format."
    echo "https://bdren.zoom.us/j/69471476777?pwd=V2Z3dEpNa0hvQ3dCMklZbG5hSKNjdz09"
    exit
fi

if [ "$MINS" -gt 59 ] || [ "$MINS" -lt 0 ]
then
    echo "The parameter <minute> should be in normal format (0-59)."
    exit
fi

if [ "$HOUR" -gt 23 ] || [ "$HOUR" -lt 0 ]
then
    echo "The parameter <hour> should be in 24-hr format (0-23)."
    exit
fi

if [ "$DATE" -gt 31 ] || [ "$DATE" -lt 1 ]
then
    echo "The parameter <date> should be in normal format (1-31)."
    exit
fi

if [ "$MNTH" -gt 31 ] || [ "$MNTH" -lt 1 ]
then
    echo "The parameter <month> should be in normal format (1-12)."
    exit
fi

################################################################################
#                             Add Meeting to Cron
################################################################################

# We just open the given url in the browser, like a dumbass. Zoom apparently
# had a dedicated protocol for opening links directly in app but it was
# deprecated. Must be some security stuff. I dunno.
# https://medium.com/zoom-developer-blog/zoom-url-schemes-748b95fd9205
#
# So for now we will have to tolerate the annoyance of a browser tab opening
# out of nowhere.
#
# The zoommtg protocol still works if you have the meeting password. The
# conference number embedded in the link can be extracted easily. But the
# password embedded in the link is some sort of hashmap. Not extractable. Maybe
# someone can reverse-engineer how the browser or the app extracts the password
# with a debugger. I cannot.
#
# usage of zoommtg protocol: zoom-client
# "zoommtg://zoom.us/join?action=join&confno=74080808553&pwd=71rEZm"
#
# This has an upside, too. We don't have to check if someone has the app
# installed or not. Bully for us.

# 19 15 24 12 * [ $(date "+\%Y") -eq 2020 ] && export DISPLAY=:0 && xdg-open "https://bdren.zoom.us/j/69471476777?pwd=V2V3dEpNa0hvQ3dCMklIbG5hSXNjdz09"
PATTERN="echo "$MINS" "$HOUR" "$DATE" "$MNTH" \* "$PAT_CMD""

# echo $PATTERN
# crontab -l | grep -Ev "^(#|$)" | grep --color "$($PATTERN)" ; echo $?
# echo "$(crontab -l ; echo ""$MINS" "$HOUR" "$DATE" "$MNTH" * "$ACT_CMD"")"
# exit

# if meeting not already scheduled
if [[ $(crontab -l | grep -Ev "^(#|$)" | grep "$($PATTERN)"; echo $?) == 1 ]]
then
    # add zoom meeting to cronjob
    echo "$(crontab -l ; echo ""$MINS" "$HOUR" "$DATE" "$MNTH" * "$ACT_CMD"")" | crontab -
else
    echo "ERROR: The meeting is already scheduled."
fi