The validateCount attribute in PowerShell function is to validate the length of an array, which means that you can pass the specific number of arguments into the parameter. In the below example we need array should contain a minimum 1 and maximum 4 values when we pass the values. For that, we will write the below script, Function ValidateArray {    Param (       [ValidateCount(1, 3)]       [String[]]$Animals    )    return $PSBoundParameters }OutputPS C:\> ValidateArray -Animals Cow, Dog, Cat Key Value --- ----- Animals {Cow, Dog, Cat}The above output is valid but when we pass ... Read More

The ValidateScript attribute is to validate the script before entering inside the function. For example, let say you want to validate the path of the file, validate the remote computer connectivity, etc. We will take here remote server connectivity example.Without the ValidateScript attribute, we would have written the script as shown below.Function Check-RemoteServer {    param (       [string]$Server    )    if(Test-Connection -ComputerName $Server -Count 2 -Quiet -ErrorAction Ignore) {       Write-Output "$server is reachable"    } else {       Write-Output "$Server is unreachable"    } }OutputPS C:\> Check-RemoteServer -Server asde.asde asde.asde is ... Read More

The ValidateLength attribute in PowerShell is used to validate the length of the String. Generally how we write the command without the mentioned attribute is using the Length method and if/else condition for the string. For Example, Function ValidateStorageName {    param (       [String]$StorageName    )    if(($StorageName.Length -gt 3) -and ($StorageName.Length -lt 15)) {       Write-Output "`nStorage Name validated"    } else {       Write-Output "`nStorage Name validation failed"    } }Output−PS C:\> ValidateStorageName -StorageName Alpha Storage Name validated PS C:\> ValidateStorageName -StorageName CN Storage Name validation failedWith the ValidateLength attribute, else ... Read More

The ValidateSet attribute in PowerShell function is to validate the values entered from the set which means, it allows only specific values from the set. To understand better consider the below example, we have an array and we need to check if entered values are among array or not then we will use the below code.Function PetAnimalsCheck {    param(       [String]$Animal    )    $Animals = "Cow", "Dog", "Cat", "Horse", "Camel", "Elephant"    if($Animals -contains $Animal) {       Write-Output "Animal is in the list of Pet Animals"    } else {       Write-Output ... Read More

Validation parameters are a set of rules that you define on the PowerShell variable and restrict users from entering some values and binding users to enter values in the specific domain. If there are not validation parameters the script would be lengthy. The ValidateRange attribute is one of them.ValidateRange AttributeThis parameter is to validate the specific range of numbers. For example, If we need users to enter a value between 5 and 100 and we simply write the script using the If/else statement as shown below.function AgeValidation {    param(       [int]$age    )    if(($age -lt 5) ... Read More

To search for the word in PowerShell and replace it in the file we will use the string operation. In fact, the Get-Content command in PowerShell is used to read almost any type of file content. In this article, we are considering one text file as shown below.Get-Content C:\Temp\TestFile.txtOutputPS C:\> Get-Content C:\Temp\TestFile.txt # In case of linux, networkInterface names are of the form eth* # In Windows, please use the network full name from Device Manager networkInterfaces: ["Microsoft Hyper-V Network Adapter" ] overrideMetricsUsingScriptFile: false scriptTimeoutInSec: 60 scriptFiles: - osType: windows filePath: monitors/NetworkMonitor/scripts/windows-metrics.bat - osType: unixBase filePath: monitors/NetworkMonitor/scripts/unix-base-metrics.shThe ... Read More

As we know $ErrorActionPreference and $ErrorAction both have the same functionality and both are used to handle terminating errors by converting Non-Terminating errors to Terminating errors. But when both the variables are used, we need to know which takes precedence.$ErrorActionPreference variable is used at the start of the script while the $erroraction variable is a common parameter and used with the cmdlet. In some cases, we might need the script to be terminated as soon as an error occurs but inside the script, we have some cmdlets which need to be ignored or continued if the error occurs. In that ... Read More

Scriptblock is a set of commands which can be executed together when they are invoked. In PowerShell, generally, we write individual commands. Scriptblock can be written with two curly brackets.Example$sb = {Get-Process powershell; Get-Service W32Time}Here we have written two commands under scriptblock. If you directly run this command, scriptblock treats them as a string.PS C:\> $sb Get-Process powershell; Get-Service W32TimeTo run the commands inside the scritblock, use Invoke-Command with the -Scriptblock parameter.Invoke-Command -ScriptBlock $sbOutputHandles NPM(K)    PM(K)    WS(K)    CPU(s)    Id    SI    ProcessName ------- ------    -----    -----    ------    --    --   ... Read More

To copy files/folders on the remote path without overwriting the existing files/folders, you can use multiple cmdlets like Copy-Item, Robocoy, and Xcopy, etc. As Copy-Item is a standard cmdlet, we will check if it's supported parameters can prevent overwriting.If Copy-Item doesn’t work then we will check its alternate command. Copy-Item simply overwrites the files and folders on the destination path and the copies newer files.For example, To copy files from the source folder C:\Test1 to the destination folder C:\Test2 below command is used and it simply overwrites the file without asking.ExampleCopy-Item C:\Test1\* C:\Test2 -Recurse -VerboseOutputPS C:\Temp> Copy-Item C:\Test1\* C:\Test2 -Recurse ... Read More

To run commands in the background in the PowerShell, you need to use Background job cmdlets. Background job means running commands/job in the background without occupying the console.Start-Job is one of the job scheduler cmdlets for PowerShell which runs PowerShell commands in the background without interacting with the current user session as a Job so that users can work in the PowerShell console without losing the control of the console while the command is running in the background.When PowerShell's job starts using Start-Job, a job returns the object immediately even if the job takes an extended time.Start-Job is designed to ... Read More