I was writing some PowerShell scripts to scan disks for certain types of malware and realized that
Get-ChildItem was kind of slow. I googled around and found this site which demonstrated using
dir as faster alternatives to
Here were the results I had searching for LNK files on my disk using both methods. First, I checked that Get-ChildItem and robocopy.exe produced the same results.
Get-ChildItem produced 442 results and took 17 seconds:
PS C:\> (Get-ChildItem -Path C:\ -Recurse -Force -ErrorAction SilentlyContinue -Filter "*.lnk" |select FullName).Length 442 PS C:\> PS C:\> (Get-History)[-1].EndExecutionTime - (Get-History)[-1].StartExecutionTime Days : 0 Hours : 0 Minutes : 0 Seconds : 17 Milliseconds : 98 Ticks : 170988716 TotalDays : 0.000197903606481481 TotalHours : 0.00474968655555556 TotalMinutes : 0.284981193333333 TotalSeconds : 17.0988716 TotalMilliseconds : 17098.8716
robocopy.exe produced 443 results and took 10 seconds. The extra result ended up being a blank line in robocopy’s output. This can be trimmed by piping robocopy’s output through
findstr /r /v '^$'
PS C:\> (robocopy C:\ NULL *.lnk /S /L /NJH /NJS /FP /NC /NDL /R:0 /W:0 /ns).Length 443 PS C:\> (Get-History)[-1].EndExecutionTime - (Get-History)[-1].StartExecutionTime Days : 0 Hours : 0 Minutes : 0 Seconds : 10 Milliseconds : 150 Ticks : 101501906 TotalDays : 0.00011747905787037 TotalHours : 0.00281949738888889 TotalMinutes : 0.169169843333333 TotalSeconds : 10.1501906 TotalMilliseconds : 10150.1906
dir, which is built into cmd.exe, was roughly as fast as
robocopy.exe when I tried, also taking 10 seconds and producing 442 results:
PS C:\> (cmd /c "dir C:\*.lnk /a-d /-c /s /b").Length 442 PS C:\> (Get-History)[-1].EndExecutionTime - (Get-History)[-1].StartExecutionTime Days : 0 Hours : 0 Minutes : 0 Seconds : 10 Milliseconds : 323 Ticks : 103231416 TotalDays : 0.000119480805555556 TotalHours : 0.00286753933333333 TotalMinutes : 0.17205236 TotalSeconds : 10.3231416 TotalMilliseconds : 10323.1416
I ran these tests a few more times and got consistent results.
Get-ChildItem always took several more seconds than
dir always finished within a second of each other.
This is good to know when writing scripts that scan large directories or the entire filesystem. Using
robocopy can likely offer a tremendous speed boost to these types of scripts.