$string =~ y/,/,/ == -1 + grep length y/ //dr, split /,/, $string #### $ alias perle alias perle='perl -Mstrict -Mwarnings -Mautodie=:all -E' $ perle 'my $x = "a,b,c"; say +($x =~ y/,/,/ == -1 + grep length y/ //dr, split /,/, $x) ? "Y" : "N"' Y $ perle 'my $x = "a,b ,c"; say +($x =~ y/,/,/ == -1 + grep length y/ //dr, split /,/, $x) ? "Y" : "N"' Y $ perle 'my $x = "a, ,c"; say +($x =~ y/,/,/ == -1 + grep length y/ //dr, split /,/, $x) ? "Y" : "N"' N $ perle 'my $x = "a, ,c"; say +($x =~ y/,/,/ == -1 + grep length y/ //dr, split /,/, $x) ? "Y" : "N"' N $ perle 'my $x = "a,,c"; say +($x =~ y/,/,/ == -1 + grep length y/ //dr, split /,/, $x) ? "Y" : "N"' N