windows 如何在 PowerShell 中比较两个日期并在几分钟内获得差异
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How to Compare two dates in PowerShell & get difference in minutes
提问by user206168
I need to compare LastWriteTime of a file and compare it to the current time. if the difference is greater then 45 minutes then I need to get a email alert.
我需要比较文件的 LastWriteTime 并将其与当前时间进行比较。如果差异大于 45 分钟，那么我需要收到电子邮件警报。
Here is what I got so far.
这是我到目前为止所得到的。
$StartDate=(GET-DATE)
$EndDate=[datetime]”01/01/2014 00:00”
NEW-TIMESPAN –Start $StartDate –End $EndDate
In code above I need to replace $EndDatewith Get-Item C:\Users\myusername\Desktop\file.html | select LastWriteTime
在上面的代码中，我需要替换$EndDate为Get-Item C:\Users\myusername\Desktop\file.html | select LastWriteTime
I need to compare the LastWriteTime of file.html with current time.
我需要将 file.html 的 LastWriteTime 与当前时间进行比较。
Please help me store
Get-Item C:\Users\myusername\Desktop\file.html | select LastWriteTimeinto $EndDate
请帮我
Get-Item C:\Users\myusername\Desktop\file.html | select LastWriteTime存入$EndDate
so I can do the compare.
所以我可以做比较。
回答by Duncan
I think this should work:
我认为这应该有效：
if (((Get-Date) - (Get-ChildItem file.html).LastWriteTime).TotalMinutes -gt 45) {
Write-Host "Old file"
}
Just to get the date into a variable would be:
只是将日期输入变量将是：
$EndDate = (Get-Item C:\Users\myusername\Desktop\file.html).LastWriteTime
or
或者
$EndDate = Get-Item C:\Users\myusername\Desktop\file.html |
select -expandproperty LastWriteTime
The select -expandpropertysyntax is needed on old versions of Powershell (prior to 3.0) when you might be accessing a property on multiple objects. I don't think it is needed even on Powershell 2 if there is only a single object.
select -expandproperty当您可能访问多个对象上的属性时，旧版本的 Powershell（3.0 之前）需要该语法。如果只有一个对象，我认为即使在 Powershell 2 上也不需要它。
