To query a Windows computer for all logged on users and log off a specific user using PowerShell, you can use the quser command to retrieve a list of logged on users and the logoff command to log off a specific user
# Prompt for the user name
$UserName = Read-Host 'Enter the user name'
# Use the quser command to get a list of logged on users
$LoggedOnUsers = quser | Select-Object -Skip 1
# Loop through the logged on users
foreach ($LoggedOnUser in $LoggedOnUsers) {
# Check if the user name matches the user we want to log off
if ($LoggedOnUser.UserName -eq $UserName) {
# Use the logoff command to log off the user
logoff $LoggedOnUser.SessionName
}
}This script prompts the user for the user name of the user that should be logged off. It then uses the quser command to retrieve a list of logged on users and pipes the output to the Select-Object cmdlet to skip the first line of the output (which is a header line).
The script then loops through the logged on users and checks the user name of each one. If the user name matches the user that should be logged off, the script uses the logoff command to log off the user.
To execute the above code on a list of servers using PowerShell, you can use the Invoke-Command cmdlet to run the code on each server remotely.
# Prompt for the user name
$UserName = Read-Host 'Enter the user name'
# Specify the list of servers
$Servers = 'Server1', 'Server2', 'Server3'
# Loop through the servers
foreach ($Server in $Servers) {
# Try to log off the user from the server
Try {
# Use the Invoke-Command cmdlet to run the code on the server
Invoke-Command -ComputerName $Server -ScriptBlock {
# Use the quser command to get a list of logged on users
$LoggedOnUsers = quser | Select-Object -Skip 1
# Loop through the logged on users
foreach ($LoggedOnUser in $LoggedOnUsers) {
# Check if the user name matches the user we want to log off
if ($LoggedOnUser.UserName -eq $args[0]) {
# Use the logoff command to log off the user
logoff ($LoggedOnUsers -split " ")[0]
}
}
} -ArgumentList $UserName
}
Catch {
# If the logoff command fails, write an error message to the console
Write-Error "Failed to log off $UserName from $Server: $_"
}
}This script prompts the user for the user name of the user that should be logged off and specifies a list of servers. It then loops through the servers and uses the Invoke-Command cmdlet to run the code on each server remotely, passing the user name as an argument.
The code that is run on the servers uses the quser command to retrieve a list of logged on users and loops through the logged on users, checking the user name of each one. If the user name matches the user that should be logged off, the logoff command is used to log off the user.
If the logoff command fails on any server, an error message is written to the console.
Keep in mind that the quser and logoff commands are external commands, which means they are not natively available in PowerShell. They may not be available on all versions of Windows, and they may behave differently depending on the version of the operating system. You may need to modify the script to fit your specific needs or use alternative cmdlets or functions to achieve the same result.
