Recently had the need to find and update most every InfoPath form in a production farm. This, mixed with the future demise of InfoPath, prompted the need to find or write a script. The below script will traverse every list and library in a given web app. The script can be easily modified to include every web app in a farm.

if ((Get-PSSnapin "Microsoft.SharePoint.PowerShell" -ErrorAction SilentlyContinue) -eq $null) 
{
                Add-PSSnapin "Microsoft.SharePoint.PowerShell"
}

$fileName = "C:\xsn-" + $(Get-Date -Format "yyyyMMddHHmmss") + ".csv"

$webApp = Get-SPWebApplication "http://webApp.sharepointed.com" 
"Title `t URL `t Type" | out-file $fileName

$(foreach($siteColl in $webApp.Sites)
{
                foreach($web in $siteColl.AllWebs)
                {
                foreach($list in $web.Lists) {                        
                
                                if ($list.BaseType -eq "DocumentLibrary" -and $list.BaseTemplate -eq "XMLForm"){
                                                "$($list.title) `t $($list.parentweb.url)$($list.DefaultViewUrl) `t Library" | out-file $fileName -Append 
                                                                
                                                
                                }elseif ($list.ContentTypes[0].ResourceFolder.Properties["_ipfs_infopathenabled"]){
                                
                                                "$($list.title) `t $($list.ParentWeb.URL)$($list.DefaultViewUrl) `t List" | out-file $fileName -Append
                                                
                                                }
												else{
												$check = 0
								foreach($c in $list.ContentTypes) {
												if($c.DocumentTemplateUrl.ToString().EndsWith("xsn") -eq $true)
												{
													$check++			
												}
												}
												if($check -gt 0)
												{
													"$($list.title) `t $($list.ParentWeb.URL)$($list.DefaultViewUrl) `t List" | out-file $fileName -Append
												}
												}
												}}})