grep nonascii without pcre

I want to grep nonascii characters from a lot of .gz files. However the below does not work on CentOS 7.6 (GNU grep v2.20) $ zcat yyyy/yyyymmdd/filname.yyyymmdd.gz | grep --color='auto' -P -n "[\x80-\xFF]" $ zgrep --color='auto' -P -n "[\x80-\xFF]" yyyy/yyyymmdd/filname.yyyymmdd.gz This perl search work $ zcat yyyy/yyyymmdd/filname.yyyymmdd.gz | perl -ne 'print "$. $_" if m/[\x80-\xFF]/' But how do I do it on mulitple files like the following? $ zgrep "[\x80-\xFF]" 2020/2020*/filename.2020*.gz