How to pass param value to the Invoke-Command cmdlet? - powershell

Question

I wrote a simple powershell script to modify hosts file on remote machines but something goes wrong.
Script:
param(
[string]$value
)
$username = 'username'
$password = 'password'
$hosts = "172.28.30.45","172.28.30.46"
$pass = ConvertTo-SecureString -AsPlainText $password -Force
$cred = New-Object System.Management.Automation.PSCredential -ArgumentList $username,$pass
ForEach ($x in $hosts){
echo "Write in $x , value: $value"
Invoke-Command -ComputerName $x -ScriptBlock {Add-Content -Path "C:\Windows\system32\drivers\etc\hosts" -Value $value} -Credential $cred
echo "Finish writing."
}
echo "End of PS script."
When run, it writes a new empty line for each hosts file. This line echo "Write in $x , value: $value" displays $value value.
What I'm doing wrong?

Answer 1

You have to pass the parameter to the scriptblock by defining a param section within your scriptblock and pass the parameters using -ArgumentList :
Invoke-Command -ComputerName $x -ScriptBlock {
param
(
[string]$value
)
Add-Content -Path "C:\Windows\system32\drivers\etc\hosts" -Value $value
} -Credential $cred -ArgumentList $value
Or you leverage the using: variable prefix:
Invoke-Command -ComputerName $x -ScriptBlock {
Add-Content -Path "C:\Windows\system32\drivers\etc\hosts" -Value $using:value
} -Credential $cred