I've got a script that's chewing through a lot of objects, and sometimes I want to kill it in the middle of the run because I see something going south. Unfortunately, I'm writing to a log file using System.IO.StreamWriter, and whenever I send a Ctrl-C, my log files are stuck open.
Is there any way I can define some kind of handler or exiting function that allows me to gracefully close filehandles and connections that I have open?
Might try using Try/Catch/Finally, putting your close() commands in the Finally block.
With PowerShell 2.0 and up, you can define a Trap which will fire when a terminating error occurs. You can define multiple traps to capture different exceptions. This could result in much cleaner code than try/catch littered everywhere, or wrapping the entire script in one big try/catch.
To terminate a script, use exit .If an exception is thrown, use try/catch/finally with close() commands in finally. If it's just an if-test, try something like this:
function Close-Script {
#If stream1 is created
if($stream1) {
$stream1.Close()
}
#Terminate script
exit
}
$stream1 = New-Object System.IO.StreamWriter filename.txt
If(a test that detects your error) {
Close-Script
}
If the amounts of streamwriters varies from time to time, you can collect them to an array and close them. Ex:
function Close-Script {
#Close streams
$writers | % { $_.Close() }
#Terminate script
exit
}
$writers = @()
$stream1 = New-Object System.IO.StreamWriter filename.txt
$writers += $stream1
$stream2 = New-Object System.IO.StreamWriter filename2.txt
$writers += $stream2
If(a test that detects your error) {
Close-Script
}
ctrl+c, you could use the function as I provided, but you would need to make the vars in the global scope(e.g. $global:writers), OR dot-source when running the script (. .\myscript.ps1), then calling Close-Script after ctrl+c