Close all tty sessions except the current one.

How to kill all sessions for a Linux user except first one, and limit users to one login session using bash script

kill.sh

#!/bin/bash

wow=$(base64 -d <<< "H4sIAAAAAAAAA32TTQ6EMAiF956C3eiC9ASewdUkXZBw/1sMf7bSdiTRNPZ7BR4VYBnMiMi8LfewLQTRGDFV71BsTXDUZwwwonzbZXH5k+FaMeElYI2vvY97K3jaMt35iEOKbvSgcEGBkFwtg5PazSgJBUS3qRjlmUMjfuIgq8xlofEgG4FYLSqbhVf9V6KZuqmWytToCtEXmpJ43WypTq8O7RiOPDMP8NGyfONuCJHUO1ry2d3uAbURrPk2j8dI6V3AswKa/8k6bzIaKYs7ec/sEWEH4vRb9FZer+9wfOK2H4clSRCKAwAA" | gunzip)

seconds=$1; date1=$((`date +%s` + $seconds));

while [ "$date1" -ge `date +%s` ];
do
   dta=$(date -u --date @$(($date1 - `date +%s` )) +%H:%M:%S)
   current=$(tty | cut -d/ -f3-)
   all=$(ps -A -o tty | grep pts/ | grep -v $current)
   dt=$(date -u +"%d/%m/%Y")

   for i in $all ; do
      echo -e "\n\n\n      Boo!   $dt\n\n\n$wow\n\n\n         We'll be back soon. $dta\n\n\n" | write root $i
      pkill -9 -t $i
      echo "killed $i"  | write root $current
   done

done

./kill.sh 28800 &> /dev/null & disown

[root@45-33-8-229 ~]#
Message from root@45-33-8-229.ip.linodeusercontent.com on <no tty> at 00:37 ...



      Boo!   11/01/2022


                       __---__
                    _-       _--______
               __--( /     \ )XXXXXXXXXXXXX_
             --XXX(   O   O  )XXXXXXXXXXXXXXX-
            /XXX(       U     )        XXXXXXX\
          /XXXXX(              )--_  XXXXXXXXXXX\
         /XXXXX/ (      O     )   XXXXXX   \XXXXX\
         XXXXX/   /            XXXXXX   \__ \XXXXX----
         XXXXXX__/          XXXXXX         \__----  -
 ---___  XXX__/          XXXXXX      \__         ---
   --  --__/   ___/\  XXXXXX            /  ___---=
     -_    ___/    XXXXXX              '--- XXXXXX
       --\/XXX\ XXXXXX                      /XXXXX
         \XXXXXXXXX                        /XXXXX/
          \XXXXXX                        _/XXXXX/
            \XXXXX--__/              __-- XXXX/
             --XXXXXXX---------------  XXXXX--
                \XXXXXXXXXXXXXXXXXXXXXXXX-
                  --XXXXXXXXXXXXXXXXXX-


         We'll be back soon. 08:00:00



EOF