我如何分割参数

Question

Writing a script to put DNS servers that are inputted as parameter to the primary network card.

The servers are inputted as: 1.1.1.1,2.2.2.2,3.3.3.3 (sometimes there are not three servers but more/less).

I want to split on the comma "," - how can I do this?

I tried this but Powershell is complaining:

[Parameter(Position = 4)]
$a = $DNSServers
$a.Split(',')

When the script is run the forth parameter is DNS Servers which are split via a comma.

UPDATE

I will try Matt's suggestion...more infoL

didn't think I would get this much response. Apologies, due to security restrictions at my place I cannot copy/paste the code that is on a server (so pain the backside in typing it all again). So, decided to copy only the bit that I needed - I thought that would be enough (obviously not!).

The script would be run as:

script.ps1 IP_ADDRESS SUBNET_MASK GATEWAY DNS_SERVER

ie: script.ps1 10.1.1.1 255.255.255.0 10.1.1.254 1.1.1.1,2.2.2.2,3.3.3.3

So the forth parameter that will be called is DNS Server (there can be multiple DNS Servers). The parameter is pulled in from an external web client that is used where the person enters the DNS Servers - but is is generally of 3 IP addresses.

oh, and the error is this - I am not too sure where it is missing the ')'

PS C:\Temp> C:\Temp\ip_assign.ps1
At C:\Temp\ip_assign.ps1:14 char:17
+ $a = $DNSServers
+                 ~
Missing ')' in function parameter list.
    + CategoryInfo          : ParserError: (:) [], ParentContainsErrorRecordException
    + FullyQualifiedErrorId : MissingEndParenthesisInFunctionParameterList

Managed to get the main parts then of what I am doing - hope this is enough:

param (

[Parameter(Mandatory=$true,
            Position = 1)]
            [string]$IP
,
[Parameter(Position = 2)]
[string]$SubnetMask = "none"
,
[Parameter(Position = 3)]
[string]$Gateway = "none" 
,
[Parameter(Position = 4)]
$a = $DNSServers
$a.Split(',')


$TeamAdaptor = Get-WmiObject -Class Win32_NetworkAdapterConfiguration | Where-Object { $_.Caption -ilike '*Virtual*'}
$TeamAdaptor.EnableStatic($IP,$SubnetMask)
$TeamAdaptor.SetGateways($Gateway)
$TeamAdaptor.SetDNSServerSearchOrder("$DNSServers")

Answer 1

I think the issue here is that you are not passing a string to the parameter like you think you are. Consider the following function.

function Get-Bagel{
param(
    $DnsServers
)
    $DnsServers.GetType().FullName
    $DnsServers
}

And then the function call

Get-Bagel 1.1.1.1,2.2.2.2,3.3.3.3

This will net the following output.

System.Object[]
1.1.1.1
2.2.2.2
3.3.3.3

Since we used array notation for inputting the variable and you didn't set a cast in the declaration $DnsServers is actually a string array. This might be what you wanted in the first place so there might not be a need to use .split() .

Your Funny Error

You are missing a bracket for param()

param (

[Parameter(Mandatory=$true,
            Position = 1)]
            [string]$IP
,
[Parameter(Position = 2)]
[string]$SubnetMask = "none"
,
[Parameter(Position = 3)]
[string]$Gateway = "none" 
,
[Parameter(Position = 4)]
[string[]]$DNSServers
)

Cast to [string[]]$DNSServers and then there is no need for splits.

Answer 2

You need to have an array variable, and then use the split function on the input string to split the contents into the array:

$a = "1.1.1.1,2.2.2.2,3.3.3.3" [array]$DnsServers = $a -split(",")

This will give you an array, $DnsServers, containing the ip addresses. In this particular case, $DnsServers[0] is 1.1.1.1, $DnsServers[1] is 2.2.2.2, and $DnsServers[2] is 3.3.3.3.

Answer 3

I think Matt gave a solid answer, but to be a little more concise here: when you specify a comma separated list of parameters, like so:

Get-Bagel Aaaaa,Bbbb,Cccc

PowerShell interprets this as three separate items, Aaaa,Bbbb and Cccc. There's no need to separate on the comma, as PowerShell automatically does it for you