When you are starting out learning how to create PowerShell scripts to accomplish responsibilities for you it is definitely thrilling when you see your script operate the way it should. Now it is time to choose it to the subsequent level and give your script the capability to make conclusions employing conditional logic statements. The PowerShell if assertion assemble is a typical way to determine problems in your script. If statements in PowerShell mimic the conclusion-earning approach persons use every working day. If a ailment is met, then some thing occurs. For instance, if it’s raining outdoors, I’ll seize an umbrella right before heading outside the house.
In this diagram, if the problem is accurate, then it runs a unique command or assertion. If the condition is wrong, it moves on to the future command or assertion. Here’s a straightforward PowerShell example.
If statements in PowerShell
The syntax of If statements in PowerShell is pretty essential and resembles other coding languages.
if (situation) assertion or command
$situation = $accurate if ( $condition ) Generate-Output "The situation was true"
The initially point the
if statement does is consider the expression in parentheses. If it evaluates to
$accurate, then it will execute the
scriptblock in the braces. If the price was
$false, then it would skip in excess of that scriptblock.
The most common issue you will use
if statements in PowerShell are for evaluating two merchandise with just about every other. Powershell has distinctive operators for various comparison situations. When you use a comparison operator, the value on the still left-hand side is when compared to the price on the proper-hand side.
-eq does equality checks among two values to make confident they are equal to every single other.
$price = Get-MysteryValue if ( 5 -eq $value ) # do one thing
In this example, I am getting a acknowledged benefit of
5 and comparing it to my
$worth to see if they match.
Other operator’s values that can be applied –
|-ge||higher than or equal|
|-lt||much less than|
|-le||a lot less than or equivalent|
|-like||string matches wildcard pattern|
|-notlike||string does not match wildcard sample|
|-match||string matches regex pattern|
|-notmatch||string does not match regex pattern|
|-includes||assortment incorporates a vlaue|
|-notcontains||selection does not comprise a worth|
|-in||price is in a assortment|
|-notin||worth is not in a collection|
|-is||both objects are the identical variety|
|-isnot||the objects are not the identical sort|
How to Use If Statements in PowerShell to Verify If A File Exists
Now that we have protected how the If assertion will work, I would like to show you a widespread use case I have made use of the If Assertion several instances just before.
I frequently find myself producing scripts that I would only like to run if a certain file exists or does not exist.
For instance, this is good if you want to run a script if an software is installed simply because a selected file will exist on a computer system.
The assertion that you can use to see if a file exists is the exam-route assertion.
Examination-Path -Route c:reportsReport1.txt
If the file exists the Output “True” will be exhibited
If (Check-Path -Path E:reportsprocesses.txt ) Duplicate-Product -Path E:reportsprocesses.txt -Vacation spot C:studies
In this case in point, I will check if “c:reportsReport1.txt” exists and if it exists, I will duplicate the file to “C:reports”. Here is the script that will do the work.
How To UseIf Statements in PowerShell To Test If A File Exists And Delete It
In the last sub-segment, you observed how to look at if a file exists and duplicate the file. What if you want to copy the file rather?
If you want to delete the file as a substitute of copying it, swap the Copy-Product command with the Get rid of-Merchandise command.
Listed here is the updated script that works by using PowerShell “IF” assertion to verify if a file exists. Then, if it exists, delete it…
$fileexists = Test-Path -Route E:reportsfirst-file.txt If ($fileexists ) Take out-Product -Path E:reportsfirst-file.txt -Force
PowerShell is an extremely powerful device that every single sysadmin must be employing. The
if statement is these a simple assertion but is a incredibly essential piece of PowerShell, permitting you to automate sophisticated duties based mostly and conditional conclusion-generating. You will discover by yourself utilizing this many occasions in nearly each script you publish. I hope this posting has presented you a better comprehension than you had ahead of.