PowerShell Interview Questions and Answers

Power shell is an extendable command shell and a scripting language for Windows. it is especially designed for system administrator.

There are four types

• Cmdlets
• PowerShell functions
• PowerShell scripts
• Executable programs

The key characteristics of PowerShell are

• PowerShell is object-based and not text based
• Commands in PowerShell are customizable
• It is a command line interpreter and scripting environment

In variables PowerShell contains strings, integers and objects.  It does not have special variables as it is pre-defined with PowerShell

Parenthesis Brackets (): Curved parenthesis style brackets are used for compulsory arguments.

Braces Brackets {}: Curly brackets are employed in blocked statements

Square Brackets []: They define optional items, and they are not frequently used

Cmdlet’s are simple build in commands written in .net language like C# or VB introduced by Windows PowerShell

Automating repetitive task with the help of PowerShell loop is known as PowerShell Loop.  Through PowerShell, you can execute for each loop, while loop and Do While loop.

If you have created a web part using VS 2010 then, you can deploy it using cntrl+f5. However, to activate the web part feature you can write a PowerShell script (.ps1) and execute it after deployment

Comparison Operators compares value in PowerShell. Four types of comparison operators are used equality, match, containment and replace.  In PowerShell, one of the key comparison operators is –eq that is used instead of “=” sign for declaring variables.  Likewise, there are other operators like –ne for “not equal” , -gt ( greater than ) or –lt (less than).

Azure PowerShell is basically an extension of Windows PowerShell. It lets Windows PowerShell users control Azure’s robust functionality. From the command line, Azure PowerShell programmers use preset scripts called cmdlets to perform complex tasks like provisioning virtual machines (VMs) or creating cloud services. APS can work programmatically too, to automate tasks. While some users complain the terminal feels “unfinished” and support is lacking, proponents point out the ease of use aids typically intensive tasks.

PowerShell pipeline is used for joining two statements such that the output of one statement becomes the input of the second.

Get command in PowerShell is used to fetch other cmdlets, for example you are looking for cmdlet between letter L and R then your PowerShell get-command will be like

# PowerShell Get – Command Range

Clear-Host

Get-Command [ L–R ]*

To map a network drive in PowerShell you have to use the command like

# PowerShell Map Network Drive

$Net = $( New – Object – ComObject Wscript.Network )

$Net.MapNetworkDrive( “S:”, \\expert\example )

In here the drive letter is “S:” and the Network share is called ‘expert’ on a computer called ‘example’

The most common way is in a WMI Query Language (WQL) statement. In this technique Wmiobject uses ‘-query’ to introduce a classic ‘Select * from’ a phrase

The second context for ‘Select’ in PowerShell is Select-String. This cmdlet checks for a word, phrase or any pattern match

Another way is Select Object

The cmdlets of windows enable you to filter the window services.  PowerShell can list which services are ‘Running’ and which are ‘Stopped’ by scripting with windows.

PowerShell file contains a series of PowerShell commands with each command appearing on a separate line. To use a text file as a PowerShell script, its filename should have.PS1 extension. To run a script you need

Type the commands in a text editor

Save the file with .ps1 extension

Execute the file in PowerShell

A hash table is also referred as dictionary. It is an array that allows you to store data in a “key-value” pair association. The “key” and “value” can be of any data and length.  To declare a hash table you have to use @ followed by curly braces.

The use of Array in PowerShell is to run a script against remote computers.  In order to create an array, you have to create a variable and assign the array.  Arrays are represented by “@”symbol, they are represented as hashtable but not followed by curly braces.

For example, $arrmachine = @ ( “machine1” , “machine2” , “machine3”)

To get all child folders in a specific folder, you have to use parameter recurse in the code.

Get-ChildItem C:\Scripts –recurse

To convert the object into HTML

Get-Process l Sort-object – property CPU –descending l convert to – HTML l Out-file “process.html”

To rename a variable,

Rename-Item- Path Env: MyVariable –NewName MyRenamedVar

The $input variable enables a function to access data coming from the pipeline

Get-WmiObject-Class Win32_Product- ComputerName . l Format-wide-column1

There are two ways to do this

get-wmiobject win32_service l where-object {$_name-like “*sql*”}

get-service sql*

There are two ways to do this.

get-wmiobject win32_service | where-object {$_.name -like “*sql*”}

get-service sql*

win32_computersystem. This can be used as follows:

PS C:\> $server = gwmi -cl win32_computersystem

PS C:\> $server.SystemType X86-based PC

When you add a variable to a double-quoted string, PowerShell replaces the variable name by its value. This feature is called variable interpolation.