Using a Queue instead of a Recursion

Rather than calling functions recursively, you may at times want to use a Queue object that you can load with fresh tasks while you are unloading things that you have already processed.

Searching a Filesystem Without Recursion

Lee Holmes has recently posted the below sample which searches an entire filesystem folder tree without recursive calls:

# create a new queue
$dirs = [System.Collections.Queue]::new()

# add an initial path to the queue
# any folder path in the queue will later be processed
$dirs.Enqueue('c:\windows')

# process all elements on the queue until all are taken
While ($current = $dirs.Dequeue())
{
    # find subfolders of current folder, and if present,
    # add them all to the queue
    try
    {
        foreach ($_ in [IO.Directory]::GetDirectories($current))
        {
                $dirs.Enqueue($_)
        }
    } catch {}

    try
    {
        # find all files in the folder currently processed
        [IO.Directory]::GetFiles($current, "*.exe") 
        [IO.Directory]::GetFiles($current, "*.ps1") 
    } catch { }
} 

Try-Catch Blocks

The try-catch blocks are required because of the .NET methods used which raise exceptions when you do not have access privileges to files or folders.

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