What is the best way to escape HTML-specific characters in a string (PowerShell)?

Question

I'm generating some simple HTML with PowerShell script, and I would like to escape strings used in result HTML (since they can contain some HTML-specific symbols).

For example:

$a = "something <somthing else>";

should be converted to the following:

"something <something else>"

Is there any built-in function for that?

Answer 1

There's a class that will do this in System.Web.

Add-Type -AssemblyName System.Web
[System.Web.HttpUtility]::HtmlEncode('something <somthing else>')

You can even go the other way:

[System.Web.HttpUtility]::HtmlDecode('something <something else>')

Answer 2

Starting with PowerShell 3.0, use [System.Net.WebUtility] for any of the four common operations:

[System.Net.WebUtility]::HtmlEncode('something <somthing else>')
[System.Net.WebUtility]::HtmlDecode('something &lt;somthing else&gt;')
[System.Net.WebUtility]::UrlEncode('something <somthing else>')
[System.Net.WebUtility]::UrlDecode('something+%3Csomthing+else%3E')

[System.Web.HttpUtility]::HtmlEncode is the common approach previous to .NET 4.0 (PowerShell 2.0 or earlier), but would require loading System.Web.dll:

Add-Type -AssemblyName System.Web

Starting with .NET 4.0 (PowerShell 3.0) [System.Web.HttpUtility]::HtmlEnocde internally calls [System.Net.WebUtility]::HtmlEncode, therefore it makes sense to leave out the middle man (System.Web.dll).

Answer 3

$SomeEmail = "user@domain.com"

$EncodedString = ([uri]::EscapeDataString($SomeEmail))

write-host $EncodedString

Using [uri] ENCODING MAKES IT MUCH EASIER