PowerShell：如果构建正确的话怎么办？ [英] PowerShell: how to get if else construct right?

问题描述

我正在尝试学习powershell，并尝试构建一个if else语句：

I'm trying to learn powershell and tried to construct a if else statement:

if ((Get-Process | Select-Object name) -eq "svchost") {
    Write-Host "seen"
    }
    else {
    Write-Host "not seen"
    }

尽管有svchost流程，但最终会变成未见。如何修改它以获得正确的结果？

This ends up into "not seen", although there is svchost processes. How to modify this to get correct results?

推荐答案

你的if-else结构是完美的，但改变if条件如下：

Your if-else construct is perfect, but change the if condition like below:

(Get-Process | Select-Object -expand name) -eq "svchost"

最初你将一个对象与svchost进行比较，后者将评估为false。使用 -expandProperty 标志，您将获得该对象的属性，该属性是一个字符串，可以正确地与svchost进行比较。

Initially you were comparing an object to the "svchost" which will evaluate to false. With the -expandProperty flag, you are getting that property of the object, which is a string and can be properly compared to "svchost".

请注意，在上面您要将包含进程名称的字符串数组与svchost进行比较。如果数组 -eq 如果数组包含另一个表达式，则为true，在这种情况下为svchost

Note that in the above you are comparing array of strings, which contains the name of process, to "svchost". In case of arrays -eq is true if the array contains the other expression, in this case the "svchost"

还有其他更好的方法可以检查：

There are other "better" ways to check as well:

if (Get-Process | ?{ $_.Name -eq "svchost"}) {
  Write-Host "seen"
}
else {
  Write-Host "not seen"
}

这篇关于PowerShell：如果构建正确的话怎么办？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！