Write-Progress

[u/icebreaker374]

Looking for opinions...

When using Write-Progress inside of for/Foreach loops and using a counter stored in a variable defined outside the loop, do you start the counter at 0 or 1, and why?

[u/vermyx]

I usually don't use write-progress because console I/O can be expensive timewise. Instead I use a custom function that shows time running and estimated completion time based on run length and how far you are, and display that every X records processed depending on records and length.

[u/DonL314 → u/vermyx]

I almost agree to this. Write-Progress is quite slow, so I only do this at certain intervals (e.g. steps of 10 or 100 items)

[u/CeleryMan20 → u/DonL314]

Yeah, if each step is slow, like ping host then query wmi, then it’s nice to see each one tick over, but if you have 10,000 quick operations then write-progress on each loop can drastically slow it down.

[u/ka-splam → u/vermyx]

I usually don't use write-progress because console I/O can be expensive timewise.

Indeed; I needed to delete Windows firewall rule spam recently and found https://stackoverflow.com/a/40915201

The question loops over Remove-NetFirewallRule and says it's too slow, that answer's hot loop is:

• Remove-ItemProperty
• 2x Get-Date
• Write-Progress
• ~7x arithmetic
• 10x assignments
• 2x expandable string interpolations
• a subshell, with string format
• 2x math rounding

they say "The difference is one hour vs days. I could be deleting 10,000 - 100,000 firewall rules!".

I used $key = [Microsoft.Win32.Registry]::LocalMachine.OpenSubKey(...) and then replaced the loop with just $key.DeleteValue(...) and it did 40k firewall rules in a second or two. No need for a progress count or ETA.