How to Use -confirm in PowerShell

Question

I m trying to take user input and before proceeding I would like get a message on screen and than a confirmation  whether user wants to proceed or not  I m using the following code but its not working   write-host  Are you Sure You Want To Proceed    -Confirm

User · Answer

For when you want a 1-liner  while  -not     choice   Read-Host  May I continue     -match  y n      Y or N

User · Answer

A slightly prettier function based on Ansgar Wiechers s answer  Whether it s actually more useful is a matter of debate   function Read-Choice      Parameter Mandatory   string  Message      Parameter Mandatory   string    Choices      Parameter Mandatory   string  DefaultChoice      Parameter    string  Question  Are you sure you want to proceed            defaultIndex    Choices IndexOf  DefaultChoice      if   defaultIndex -lt 0            throw   DefaultChoice not found in choices              choiceObj   New-Object Collections ObjectModel Collection Management Automation Host ChoiceDescription       foreach  c in  Choices             choiceObj Add  New-Object Management Automation Host ChoiceDescription -ArgumentList  c               decision    Host UI PromptForChoice  Message   Question   choiceObj   defaultIndex      return  Choices  decision      Example usage   PS gt   r   Read-Choice  DANGER          amp apple    amp blah    amp car    amp blah   DANGER       Are you sure you want to proceed   A  apple   B  blah   C  car      Help  default is  B    c PS gt  switch  r      amp car    Write-host  caaaaars          amp blah    Write-Host  It s a blah day      amp apple    Write-Host  I d like to eat some apples       caaaaars

User · Answer

Read-Host is one example of a cmdlet that -Confirm does not have an effect on -Confirm is one of PowerShell s Common Parameters specifically a Risk-Mitigation Parameter which is used when a cmdlet is about to make a change to the system that is outside of the Windows PowerShell environment  Many but not all cmdlets support the -Confirm risk mitigation parameter   As an alternative the following would be an example of using the Read-Host cmdlet and a regular expression test to get confirmation from a user    reply   Read-Host -Prompt  Continue  y n   if    reply -match   yY              Highway to the danger zone      The Remove-Variable cmdlet is one example that illustrates the usage of the -confirm switch   Remove-Variable  reply  -Confirm   Additional References  CommonParameters  Write-Host  Read-Host  Comparison Operators  Regular Expressions  Remove-Variable

User · Answer

-Confirm is a switch in most PowerShell cmdlets that forces the cmdlet to ask for user confirmation  What you re actually looking for is the Read-Host cmdlet    confirmation   Read-Host  Are you Sure You Want To Proceed   if   confirmation -eq  y           proceed     or the PromptForChoice   method of the host user interface    title       something   question    Are you sure you want to proceed     choices   New-Object Collections ObjectModel Collection Management Automation Host ChoiceDescription   choices Add  New-Object Management Automation Host ChoiceDescription -ArgumentList   amp Yes     choices Add  New-Object Management Automation Host ChoiceDescription -ArgumentList   amp No      decision    Host UI PromptForChoice  title   question   choices  1  if   decision -eq 0        Write-Host  confirmed    else       Write-Host  cancelled        Edit   As M-pixel pointed out in the comments the code could be simplified further  because the choices can be passed as a simple string array    title       something   question    Are you sure you want to proceed    choices      amp Yes     amp No    decision    Host UI PromptForChoice  title   question   choices  1  if   decision -eq 0        Write-Host  confirmed    else       Write-Host  cancelled

User · Answer

write-host does not have a -confirm parameter   You can do it something like this instead        caption    Please Confirm           message    Are you Sure You Want To Proceed        int  defaultChoice   0      yes   New-Object System Management Automation Host ChoiceDescription   amp Yes    Do the job        no   New-Object System Management Automation Host ChoiceDescription   amp No    Do not do the job        options    System Management Automation Host ChoiceDescription     yes   no       choiceRTN    host ui PromptForChoice  caption  message   options  defaultChoice   if    choiceRTN -ne 1         Your Choice was Yes    else       Your Choice was NO

User · Answer

This is a simple loop that keeps prompting unless the user selects  y  or  n    confirmation   Read-Host  Ready   y n   while  confirmation -ne  y         if   confirmation -eq  n    exit       confirmation   Read-Host  Ready   y n

User · Answer

Write-Warning  quot This is only a test warning  quot  -WarningAction Inquire  from  https   serverfault com a 1015583 584478

User · Answer

Here is the documentation from Microsoft on how to request confirmations in a cmdlet  The examples are in C   but you can do everything shown in PowerShell as well   First add the CmdletBinding attribute to your function and set SupportsShouldProcess to true  Then you can reference the ShouldProcess and ShouldContinue methods of the  PSCmdlet variable   Here is an example   function Start-Work        lt        SYNOPSIS Does some work      PARAMETER Force         Perform the operation without prompting for confirmation       gt       CmdletBinding SupportsShouldProcess  true       param            This switch allows the user to override the prompt for confirmation          switch  Force           begin         process           if   PSCmdlet ShouldProcess  Target                  if  -not   Force -or  PSCmdlet ShouldContinue  Do you want to continue     Caption                       return   user replied no                              Do work                      end

User · Answer

Here s a solution I ve used  similiar to Ansgar Wiechers  solution    title    Lorem   message    Ipsum    yes   New-Object System Management Automation Host ChoiceDescription   amp Yes    This means Yes   no   New-Object System Management Automation Host ChoiceDescription   amp No    This means No    options    System Management Automation Host ChoiceDescription     yes   no    result    host ui PromptForChoice  title   message   Options  0   Switch   result                   0    You just said Yes              1    You just said No

User · Answer

I prefer a popup    shell   new-object -comobject  WScript Shell   choice    shell popup  Insert question here  0  Popup window title  4 32    If  choice equals 6  the answer was Yes If  choice equals 7  the answer was No

[powershell] How to Use -confirm in PowerShell

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