MAC address string comparison fails - string

Question

I try to extract a computername from a txt file $pcliste using a string comparison to the MAC address of the local machine. the text file contains:
super-pc 00:15:5D:FF:0B:33
av-client4 00:15:5D:FF:0B:38
temp 00:15:5D:FF:0B:39
I use the following PowerShell code:
$macadresse = Get-WmiObject Win32_NetworkAdapterConfiguration | select macaddress
$macadresse = $macadresse.macaddress
$pcnamen = Get-Content -Path $pcliste
$computername = "TEMP-NAME"
for ($i=0; $i -lt $pcnamen.Length; $i++) {
$string = $pcnamen[$i]
if ($string -match $macadresse) {
write "MAC found!"
$index = $pcnamen[$i].IndexOf(" ")
$computername = $pcnamen[$i].substring(0, $index)
}
}
the MAC adress of my test VM is 00:15:5D:FF:0B:38, but the string comparison in the loop remains false.
For testing I already put the MAC in a string variable instead of extracting it using the Get-WmiObject, and this works.
I also tried to convert the extracted macadress to a string using [string]$macadress.
I assume it's some kind of datatype/objecttype problem that causes the -match to fail.

Answer 1

What about a hash table to put the MAC as key and pc name as value in.
$MyMACs = Get-WmiObject win32_networkadapterconfiguration|Select -Expand MacAddress
$MyMACs
$PcHash = #{}
ForEach ($Row in (Get-Content '.\pcliste.txt')) {
$PcHash.Add($Row.Split(' ')[1],$Row.Split(' ')[0])
}
ForEach($Mac in $MyMACs){
IF ($PcHash[$Mac]){
"Found {0} for MAC {1}" -f $PcHash[$Mac],$Mac
}
}
Or more basic
$MyMACs = Get-WmiObject win32_networkadapterconfiguration|Select -Expand MacAddress
ForEach($Mac in $MyMACs){
Select-String -Path '.\pcliste.txt' -Pattern $MAC|ForEach-Object{$_.Line}
}

Answer 2

try to modify like this:
$string = $pcnamen[$i] -split " "
if ($macadresse -contains $string[1]) {
you can simplify your code like this :
$pcnamen = import-csv $pcliste -Delimiter ' ' -Header Computer, Mac
Get-WmiObject Win32_NetworkAdapterConfiguration | %{
$Mac=$_.macaddress
$pcnamen | where Mac -eq $Mac
}