use strict;
my $str = 'activity_id eq 9 and
status eq \'active asdf activity_id eq 9 and var gt 3\'
status eq \'active\' and activity_id eq 9
activity_id eq 9
status eq \'active\'
status eq \'active asdf activity_id eq 9 and var gt 3\' and activity_id eq 9
activity_id eq 9
status eq \'active\'
status eq \'active
and done\'
activity_id eq 9 and status eq \'active\'
activity_id eq 9 or status eq \'active\'
status eq \'active\'
and activity_id eq 9
status eq \'active\' or activity_id eq 9
status eq \'active and done\' and activity_id eq 9
status eq \'active and done\' or activity_id eq 9
activity_id eq 9 and start_date le \'2021-03-20T00:00:00-00:00\'
start_date le \'2021-03-20T00:00:00-00:00\'';
my $regex = qr/((?'field'[a-z_]+)\s+(?'operator'eq|ne|gt|lt|ge|le)\s+(?'value'(?>'[\w\-:\s]+')|(?>[\w]+))(\s+(?'join'and|or))?)+/p;
my $subst = '';
my $result = $str =~ s/$regex/$subst/rg;
print "The result of the substitution is' $result\n";
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 Perl, please visit: http://perldoc.perl.org/perlre.html