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Why writing PowerShell script

This is one of the most interesting question about writing in PowerShell script... why we need it? PowerShell was released in 2006 and I have no interest in it for so many years until I was doing the repeating works on many servers. This includes installing applications into many servers, updating the servers, checking the server health, checking the database backup, reviewing the event logs, ... all repetitive tasks should be done and can be done better with scheduled program. Here's some reasons why you need to write script with PowerShell: Consistency issue - installing web applications into IIS by using PowerShell - as a result, the application pool name, folder permission will be definitely looks the same. No more issue with typo error or application name with different upper and lower cases. The web application setup in all server will be consistent. No more naming issue. No more directory structure issue (because the script must work for the same directory structure which fo...
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Preload your favorite scripts in PowerShell

Try this - if you have developed many useful scripts for yourself, how to avoid call Import-Module in all your new script? To solve this, we must find a way to preload your favorites. The trick is to create "profile.ps1" file and save it in your profile path. You will find your profile path by executing the following code: $profile.CurrentUserAllHosts After you have found out the path, create a "profile.ps1" and write all Import-Module lines to preload your favorites.
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Failed to download from Internet

The following codes are downloading a text file from the Internet. It looks simple and straight forward. $u2 = "https://my-test-web.com/my-file.txt" $f2 = "my-file.txt" Invoke-WebRequest -Uri $u2 -OutFile $f2 The above code looks good and we never expect download failure except that Internet connection has broken down. But, if you look at the value of $u2, you might notice that it is calling HTTPS which require Powershell to validate the SSL certificate. So, there is a chance for the above code failed when the web server disabled Tls v1.1 and below. To resolve/avoid this issue, you must change the environment setting first before calling Invoke-WebRequest. # enforce Tls1.2 [Net.ServicePointManager]::SecurityProtocol = [Net.SecurityProtocolType]::Tls12 $u2 = "https://my-test-web.com/my-file.txt" $f2 = "my-file.txt" Invoke-WebRequest -Uri $u2 -OutFile $f2
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Tricky ConvertTo-Json in Powershell

ConvertTo-JSON is very useful for generating any runtime value into JSON format. For example, the following code convert an array into JSON format: # save the to json format $list = @(     "Apple",     "Banana" ) $list | ConvertTo-Json And the output will look like this: [     "Apple",     "Banana" ] But, there is a catch on the following situation where it does not convert the array into JSON format. Instead, it just returns a string.  $trick = @(     "Coconut" ) $trick | ConvertTo-Json And the output will look like this: "Coconut" This is not a mistake of the above code. Instead, the correct code should look like the following: ConvertTo-Json -InputObject $trick Output: [     "Coconut" ]
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Handling XML in Powershell

In Powershell, it is very easy to handle XML data as compare to C#. This is because Powershell is not statically type and the property access can be determined at runtime. The following example shows how to change the value in an AppSetting node: $f = "$PSScriptRoot\web.config" # read xml file - the most import is "[xml]" type cast in front of $xml variable. [xml]$xml = Get-Content $f # show the nodes in "appSettings" $xml.configuration.appSettings.add | Format-Table -AutoSize # change the appSetting $xml.configuration.appSettings.add[1].value = "1" # save changes to file $xml.Save($f)
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View the binding for the website in IIS

To view the binding, you need to call Get-WebBinding API.   Import-Module WebAdministration    Get-WebBinding -Name 'default web site' Explanation: 1. We import the WebAdministration PS module into memory so that we can call any of the API that interacts with IIS. 2. Call Get-WebBinding to retrieve the binding for the "default web site" (you might have website that is different name). In case you need to find out all website names, please run the following codes:    Get-ChildItem IIS:\Sites | select name
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Get all website entries in IIS

It's very easy to get the list of the website entries in IIS with 3 lines of code.   Import-Module WebAdministration   cd IIS:\Sites   Get-ChildItem | select name Explanation: 1. We need to import the WebAdministration PS module. This module includes all the necessary API for Powershell to interact with IIS. 2. The second line is to change the current location to IIS Sites folder. 3. Finally, get all the items in the current location.
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