[Powershell] IF THEN ELSE

[box_l]

A client wants a very basic way of finding the owner of lost USB sticks.

 

I have written this powershell script

 

#get serial from usb

$serial = gwmi Win32_USBControllerDevice |%{[wmi]($_.Dependent)} | select-string USBSTOR | foreach{$_.tostring().split("\\")[8].split("&")[0]}

#cat txt file for existing serial and if exist display name

$exists = cat .\somefile.txt | select-string $serial

# not equal 0

if ($exists -ne 0) 
{
echo $exists
}
else
{
$name = read-host "please enter USB owner name"

echo "$serial $name" >> ./somefile.txt
}

 

which does everthing but the "Else" part.

 

Any ideas?

 

BoX

[jamesb]

Try if ($exists -ne $null) rather than 0.

[box_l]

 

Perfect!

 

Many thanks for the speedy answer.

 

BoX

[jamesb]

Just don't ask how many times I've been caught out by the difference between 0 and null.

[mac_shinobi]

Just don't ask how many times I've been caught out by the difference between 0 and null.

 

Difference is one puts you into invalid memory and the other one works

 

I was going to suggest also trying or using the equivelant of Select Case or Switch ( depending on the language used ), not sure what powershell uses, I presume Switch