#include <StringConstants.au3> ; to declare the Constants of StringRegExp
#include <Array.au3> ; UDF needed for _ArrayDisplay and _ArrayConcatenate
Local $sRegex = "<iframe.*?src="(?![^"]*(?:youtube|vimeo|soundcloud)).*?<\/iframe>"
Local $sString = "<p><iframe src="http://www.3you3tube.com/embed/YoX1yc92MOU" width="500" height="300" frameborder="0" scrolling="auto"></iframe></p>" & @CRLF & _
"29 <p>text daily to place domain staff as volunteers with charity partners, we know all too well that the "V" word can sometimes be misunderstood. Occasionally seen as a dusty, worthy word, it can conjure images of coffee mornings and bric-a-brac stalls. So its not always as easy as you might think to get people to embrace their inner-volunteer. That's why the <a href="http://www.domain.co.uk/sdfn/2010/11/connect-create-domain-volunteers.shtml">Conne<p><iframe src="http://www.youtube.com/embed/YoX1yc92MOU" width="500" height="300" frameborder="0" scrolling="auto"></iframe></p>"
Local $aArray = StringRegExp($sString, $sRegex, $STR_REGEXPARRAYGLOBALFULLMATCH)
Local $aFullArray[0]
For $i = 0 To UBound($aArray) -1
_ArrayConcatenate($aFullArray, $aArray[$i])
Next
$aArray = $aFullArray
; Present the entire match result
_ArrayDisplay($aArray, "Result")
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for AutoIt, please visit: https://www.autoitscript.com/autoit3/docs/functions/StringRegExp.htm