Powersell - create scheduled task in Windows Task Scheduler - part 1

Explanation

Windows Task Scheduler is a utility that helps to execute any process periodically. For example, you want to sync your working files on a daily basis, scan a virus, process some data, etc.

In a nutshell, a task has the following components:

• Action or multiple actions - which is the process that you want to run periodically. We use New-ScheduledTaskAction to create a new action object.
• Trigger - which is the time to run the process and it can have multiple timing. We use New-ScheduledTaskTrigger to create a new trigger.
• Security context - any process must run in a valid security context. We can set the context using New-ScheduledTaskPrincipal.

For illustration purpose, the following script creates an on demand task. This means, it requires the user to manually trigger the task.

$task_folder = "\myTasks\"

$task_name = "myTask2"
# this can be any Powershell script.
$ps_script_file = "d:\temp5\test-script.ps1"

## The first line will show err if $task_folder does not exist.
## The second line will not show any error if $task_folder does not exist.
#$exist = Get-ScheduledTask -TaskPath $task_folder | Where-Object {$_.TaskName -eq $task_name}

$exist = Get-ScheduledTask | where {$_.TaskPath -eq "\myTasks\" -and $_.TaskName -eq $task_name }

if (!$exist)  {
    $axn = New-ScheduledTaskAction -Execute "powershell.exe" -Argument "-ExecutionPolicy Bypass ""$ps_script_file"""

    Register-ScheduledTask -TaskName $task_name  -TaskPath $task_folder -Action $axn

    Write-Host "created new task"
}
else {
    Write-Host "The task already exists"
}

The contents of test-script.ps1

$dt = (get-date).ToString()
Set-Content -Path "d:\temp5\test-ps-output.txt" -Value $dt

Advantages on using Powershell to schedule a task

• You can write a script like above and runs it on multiple servers. The task created in those server can have the same settings or different settings (such as different trigger timing).
• Setting up the task will become easier job once you have the script that looks like above.
• Changing the triggering timing has become easier.
• Changing the task action has become easier.

Disadvantages on using Powershell to schedule a task

• You have to spent a few hours in writing the script for creating schedule task.

Conclusion

Powershell is helpful, convenient and fast in scheduling many tasks in one go because adding task through the GUI is time consuming. In case that you are managing more than one server, Powershell is the best way to create schedule task because the task will be created with the same setting (i.e., this enforce the "standardization of settings" which leads to easier server management).

Related posts

1. Create scheduled task in Windows Task Scheduler - part 1
2. Create scheduled task in Windows Task Scheduler - part 2
3. Create scheduled task in Windows Task Scheduler - part 3

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