Hello, I am currently writing a bash script that checks if a user has logged in more than once, by checking the output of 'ps x' The output is processed so only two columns of data are available - the PID and the username. If the script finds that two users (with the same username) are logged in, both the users PIDs should be passed to the 'kill' command so they both get disconnceted. I'm slowly getting there: Code: #!/bin/bash declare users=`ps x | grep priv | tr -s " " | cut -f 1,6 -d ' '` # Main Loop # if [ $user1 == $user2 ] # then echo "Match found, disconnecting user '$user1'" # fi echo $users # Quit cleanly exit Right now, the script just prints out the current users and their PIDs. Unfortunately I don't know how to go any further due to my lack of experience / knowledge. Any help on how to compare every username to every other username, and extract PIDs if/when matches are found would be highly appreciated. PS I am aware that there is a way to limit concurrent logins, and this is not what I want. I want both users to be D/Cd.
have you tried Code: if [ "$user1" = "$user2" ]; then But that will match "" as well, you possibly need to check if the $user1 variable is not empty first.
Hello, No I have not tried that, becuase I don't know how to actually read the users / PIDs into a variable properly to begin with.
Code: pids=$(ps ax| grep sshd | grep "@pts/" | awk '{ print $1 }') users=$(ps ax| grep sshd | grep "@pts/" | awk '{ print $6 }' | sed -r "s/@pts\/[0-9]?//") YMMV
Hello topdog, thanks for the reply. I've already figured out how to actually pull out the usernames and PIDs. pids=$`ps x | grep priv | tr -s " " | cut -f 1 -d ' ` users=$`ps x | grep priv | tr -s " " | cut -f 6 -d ' '` My problem is with actually processing them. I am unfamiliar with how to write loops etc. TIA!
Code: #!/bin/bash declare -a array1 declare -a array2 users=$(ps x | grep priv | tr -s " " | cut -f 6 -d ' ') pids=$(ps x | grep priv | tr -s " " | cut -f 1 -d ' ') array1=($users) array2=($pids) for i in $(seq 0 $((${#array1[*]} - 1))); do testvalue=${array1[$i]} for x in $(seq 0 $((${#array1[*]} - 1))); do if [ "$x" = "$testvalue" ]; then kill -9 ${#array2[$i]} fi done done
Thanks topdog! Unfortunately it appears this script is not running properly :\ I have several users logged in like so: 416 breakaway 30459 breakaway 30490 breakaway 30521 vent 30553 devon 32743 xerxes But it didn't kill the 3 'breakaway' users :\
Okay i did not test, but i have just checked it seems like your commands to check the users does not work.
Code: #!/bin/bash declare -a array1 declare -a array2 pids=$(ps ax| grep sshd | grep "@pts/" | awk '{ print $1 }') users=$(ps ax| grep sshd | grep "@pts/" | awk '{ print $6 }' | sed -r "s/@pts\/[0-9]?//") array1=($users) array2=($pids) for i in $(seq 0 $((${#array1[*]} - 1))); do testvalue=${array1[$i]} for x in $(seq 0 $((${#array1[*]} - 1))); do intestvalue = ${array1[$x]} if [ "$intestvalue" = "$testvalue" ]; then kill -9 ${#array2[$i]} fi done done
Please test before use in a production environment. Code: #!/bin/bash declare -a array1 declare -a array2 pids=$(ps ax| grep sshd | grep "@pts/" | awk '{ print $1 }') users=$(ps ax| grep sshd | grep "@pts/" | awk '{ print $6 }' | sed -r "s/@pts\/[0-9]?//") array1=($users) array2=($pids) for i in $(seq 0 $((${#array1[*]} - 1))); do testvalue=${array1[$i]} count=0 for x in $(seq 0 $((${#array1[*]} - 1))); do intestvalue = ${array1[$x]} if [ "$intestvalue" = "$testvalue" ]; then let count=count+1 #check if the name has appeared more than one and kill if [ $count -gt 1 ]; then kill -9 ${#array2[$i]} fi fi done done
