1. while (length($line)) {
2.   ($quote, $quoted, undef, $unquoted, $delim, undef) =
3.    $line =~ m/^(["'])                 # a $quote
4.             ((?:\\.|(?!\1)[^\\])*)    # and $quoted text
5.                \1                     # followed by the same quote
6.                ([\000-\377]*)         # and the rest
7.               |                       # --OR--
8.               ^((?:\\.|[^\\"'])*?)    # an $unquoted text  
9.               (\Z(?!\n)|(?-x:$delimiter)|(?!^)(?=["']))  
                                       # plus EOL, delimiter, or quote
10.             ([\000-\377]*)           # the rest
11.             /x;                      # extended layout
12. return() unless( $quote || length($unquoted) || length($delim));