Powershell删除了更多文件，不是吗？

Question

I'm using the following snippet of code in a powershell script to clean up files that we no longer need, however this appears to delete everything (thank God for backups...) and not just those modified older than $limit, can anyone explain this behavior?

param (
    [int]$daystokeep = 548 # default to 18 months 
)

$limit = (Get-Date).AddDays(-1 * $daystokeep) # 18 months

Get-ChildItem -Path $path -Recurse -Force | Where-Object { !$_.PSIsContainer -and $_.ModifyTime -lt $limit } | Remove-Item -Force

Answer 1

FileInfo objects have no ModifyTime property, so your comparison basically evaluates to:

$null -lt $limit

which is always $true .

Change the property name to LastWriteTime :

$_.LastWriteTime -lt $limit