Powershell如果

Question

I'm having an issue with the if then.

    $result = getMachineInfo $rlprddeploy $mdt
"-MachineID-    -LastContactAt-          -LastIP-   -Deployment Receiver Version-"
$machine = $result.MachineID
$result | % { '{0,-10} {1,23} {2,16} {3,20}' -f $_.MachineID, $_.LastContactAt, $_.LastIP, $_.DeploymentReceiverVersion }
#$result | ft -auto

if $_.DeploymentReceiverVersion is less than 5.46.54 then I'm going to send a file to do an update. If the version is 5.55 then nothing needs to be done.

I've been banging my head against this for a week now and I can't figure it out. Every $_.blahblah is information pulled from an SQL table on a server.

We've been sending out updates manually and I'd like to stop that.

Answer 1

PowerShell's If statement can be written just like any C like language:

if ($true) {Write-Host "True Yo" }

That said, you haven't posted exactly what your issues is, so this somewhat generic:

Creating a custom object:

$dep = New-Object psobject -Property @{DeploymentReceiverVersion = "5.000.11"; AppName = "OxenTails" }

Comparing this is going to pose a potential problem:

$dep.DeploymentReceiverVersion.GetType()

The version is a string, so the comparison is comparing strings:

$dep.DeploymentReceiverVersion -lt "5.000.12" 

gives an expected result, but

$dep.DeploymentReceiverVersion -lt "5.000.101"

does not.

This however could work to compare each set of numbers:

$parts = $dep.DeploymentReceiverVersion.Split('.')
if ([int]$parts[0] -lt 6 -and [int]$parts[1] -lt 001 -and [int]$parts[2] -lt 101) {
#Do Stuff!
}

Additionally, as pointed out by @TheMadTechnician there is the System.Version type [Version]

It can be used with one of the overload methods:

[Version]::new(parts[0],parts[1], parts[2]) -lt [Version]::new(5,46,54)

Which is marginally more readable.