Detecting if IP Address Entered

This topic contains 6 replies, has 5 voices, and was last updated by  107 1 month, 1 week ago.

  • Author
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  • #6697

    Lery
    Participant

    I'm trying to do something that I thought should be simple.  Apparently, it's not as simple to me as I thought.  I'm creating a PowerShell script that will eventually use invoke-command.  Therefore, I want to make sure that a computer name was entered, and not an IP address.  This is what I have:

    $test = '127.0.0.1'
    If ($test -contains '...' ) {Write-Host 'IP Address Detected'}
    else {Write-Host 'Computer Name Detected'}

    I'm only using Write-Host for testing purposes.  I do not plan on using it in the final script 🙂

    I'm open to any ideas for the best approach to detecting if the variable contains an IP address or not.

     

  • #6698

    Lery
    Participant

    A minute after I posted the above, I found http://technet.microsoft.com/en-us/magazine/2007.11.powershell.aspx by our own Mr. Wonderful.  aka Don Jones 🙂

    Based on that, this works.

    $test = '192.168.1.50'
    If ($test -match "\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}" ) {Write-Host 'IP Address Detected'}
    else {Write-Host 'Computer Name Detected'}

    Best way, maybe?  I'm not validating the data.  Just making sure the data looks right.

  • #6700

    Richard Siddaway
    Moderator

    You could simplify it to this

    if ($test -notmatch "[a-z]"){Write-Host "IPAddress"}else{Write-Host "Computer Name"}

    because an IP address shouldn't contain letters

  • #6701

    Lery
    Participant

    Richard,

    I like that idea!  I wonder if I would run into that odd circumstance that has a computer name as '567'.  Doubtful, but I've seen many creating computer names in my time 🙂

  • #6702

    Matt Tilford
    Participant

    If you want to go the whole hog regular-expressions.info have more examples here. They have a regex that will go as far as matching valid ip's, whereas the example you gave would accept 999.999.999.999 as valid. Obviously that match is not a concern here, but i thought it was worth mentioning.

  • #6703

    Kamil Tatar
    Participant

    Hi,

    You can use this:

    $ip = "192.168.0.1"
    $IpCheck = ($ip -As [IPAddress]) -As [Bool]

    if($IpCheck) {
    "OK – IP"
    } else {
    "ERROR – NO IP"
    }

     

     

  • #74917

    107
    Participant

    function FIND_NODE {

    Write-host "Enter IP to Modify:(>" -NoNewline
    $INPUT = Read-Host
    $script:INPUT = $INPUT.Trim()
    $Ipcheck = ($script:INPUT -AS [IPAddress]) -as [Bool]

    if ($Ipcheck -ne "TRUE") {

    Write-Host "$script:INPUT is not a valid IP"; FIND_NODE

    }
    }

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