This is not a valid regular expression. The interpretation of (\.|^)*
is:
An arbitrary number of dots or line starts
Does "an arbitrary number of line starts" make sense? I guess not and awk
might die while trying to reference to the same anchor multiple times. This may very well end up in an infinite loop.
You either want to
- Just get rid of the
*
. This would blockmetric.gstatic.com
and all of its subdomains. - If you want to block anything ending in metric.gstatic.com (so also
ABCDEFmetric.gstatic.com
), the regex should not have an initial anchor and should look like:metric\.gstatic\.com$
What do you really want to achieve with this regex? We can fix it together if you like.