Handle Directory Exists Exception - powershell

Question

I am new to PowerShell. I have a piece of code which checks whether a folder "ilalog" exists or not. When I run this script first time, it is checking for the folder "ilalog",if it does not exist,it is creating. When I run the script second time. I receive the error below:
An item with the specified name D:\Temp\ilalog already exists
"FullyQualifiedErrorId :
DirectoryExist,Microsoft.PowerShell.Commands.NewItemCommand".
how to handle this exception
I have tried using try and Catch block
$rgflder="ilalog"
[bool]$checkrg=Test-Path D:\Gdump\$rgfolder -PathType Any
if ( $checkrg -eq $False)
{
try{
New-Item -Path "D:\Gdump" -Name "$rgflder" -ItemType "directory"
}
catch [System.IO.IOException]
{
if ($_.CategoryInfo.Category -eq $resExistErr) {Write-host "Dir Exist"}
}
}
else
{
Write-Output "Directory Exists"
}

Answer 1

If you want to continue processing your script while taking action based on an error type, a simple way is to just examine the $error variable. Using Trap may be an option as well.
$error.clear()
New-Item -Path "D:\Gdump" -Name "$rgflder" -ItemType "directory"
if ($error[0].Exception.GetType().Fullname -eq 'System.IO.IOException') {
"Dir Exists"
}
else {
"Dir was created"
}
If you want to use try-catch, you need to treat your non-terminating error as a terminating error to activate the catch block. You can do this with -ErrorAction Stop.
try {
New-Item -Path "D:\Gdump" -Name "$rgflder" -ItemType "directory" -ErrorAction Stop
}
catch [System.IO.IOException]
{
"Exception caught!"
}
Alternatively, you can manage this within your session by setting $ErrorActionPreference = 'Stop', which will apply to all commands within that session.
Keep in mind that the value passed to -ErrorAction overrides the setting in $ErrorActionPreference. Also, error action settings have no affect on terminating errors. So you cannot expect to set -ErrorAction Continue and have code continue processing on a terminating error.
Many commands return objects that may or may not be terminating errors. You will find more success explicitly, specifying when you want to throw a terminating error.
You can read more about error action preference at About Common Parameters. I actually like Everything About Exceptions for exception handling in PowerShell.

Answer 2

Why not simply do like below?
$rgflder="ilalog"
# combine the path and foldername
$rgPath = Join-Path -Path 'D:\Gdump' -ChildPath $rgflder
# test if the folder already exists
if (Test-Path $rgPath -PathType Container) {
Write-Output "Directory Exists"
}
else {
# if not, create the new folder
try {
$null = New-Item -Path $rgPath -ItemType Directory -ErrorAction Stop
Write-Output "Created directory '$rgPath'"
}
catch {
# something terrible happened..
Write-Error "Error creating folder '$rgPath': $($_.Exception.Message)"
}
}