Very Simple Chat Program - Updating Chat Log? - powershell

Question

I have made a very simple chat program. All it does is saves the message as a new line in a txt file and displays that txt file in a richtextbox. The issue I am having is the user has to click "Update" to update the chat log. I wrote a loop that would check every second to see if there was a new message, however this locks up the form and if the user wants to send a message during that time, they would need to kill the form.
Is this in anyway possible? Either auto updating the chat log when a new line is added to the txt document or even a regular interval?
Currently what I am using is this:
$i = 1
While ($i -eq 1)
{
sleep -Seconds 1
$BEFORE = $richtextbox1.Text
$CHATLOG = "\\NetworkShareEveryoneHasAccess\Chat.txt"
$TOOUTPUT = Get-Content $CHATLOG | Out-String
$richtextbox1.Text = $TOOUTPUT
$AFTER = $richtextbox1.Text
if ($BEFORE -ne $AFTER)
{
$i = 0
$richtextbox2.Enabled = $true
$richtextbox2.SelectionStart = $richtextbox2.TextLength;
$richtextbox2.ScrollToCaret()
$richtextbox2.Focus()
}
}
Again, the problem with this is that is freezes the form while it is checking to see if a new message (new line in the txt file).
With my limited knowledge of PowerShell, I want to say this is not possible, but as I said my PowerShell knowledge is limited.

Answer 1

Instead of using sleep and checking the whole file for any new writes, you could separate the processes for writing and reading from the file. Then in the reading process use a form of Get-Content -Path Chatfile.log -Tail 1 -Wait which will return a new line everytime the Chatfile is altered. This shows the concept:
$EXITFLAG = 0
$chatLog = "chat.txt"
$logRead = Start-Process powershell.exe -PassThru -ArgumentList "-file logread.ps1"
while ($EXITFLAG -eq 0)
{
$userTxt = Read-Host "Enter some text to chat (Q to exit)"
if ($userTxt -eq "q")
{
$EXITFLAG = 1
}
else
{
$userTxt >> $chatLog
}
}
Stop-Process $logRead.Id