- | grep -Eo '[&?]'"$2"'=[^&]*' \
- | sed -rn "${3:-1}"'{s;^[^=]+=;;; s;\+; ;g; s;\\;\\\\;g; s;%;\\x;g; p}'
+ | grep -Eo '&'"$2"'=[^&]*' \
+ | sed -rn "${3:-1}"'{s;^[^=]+=;;; s;\+; ;g; s;\\;\\\\;g;
+ # Hexadecimal { %00 - %FF } will be transformed to octal { \000 - \377 } for posix printf
+ s;%[0123].;&\\0;g; s;%[4567].;&\\1;g; s;%[89AB].;&\\2;g; s;%[CDEF].;&\\3;g;
+ s;%[048C][0-7]\\.;&0;g; s;%[048C][89A-F]\\.;&1;g; s;%[159D][0-7]\\.;&2;g; s;%[159D][89A-F]\\.;&3;g;
+ s;%[26AE][0-7]\\.;&4;g; s;%[26AE][89A-F]\\.;&5;g; s;%[37BF][0-7]\\.;&6;g; s;%[37BF][89A-F]\\.;&7;g;
+ s;%.[08](\\..);\10;g; s;%.[19](\\..);\11;g; s;%.[2A](\\..);\12;g; s;%.[3B](\\..);\13;g;
+ s;%.[4C](\\..);\14;g; s;%.[5D](\\..);\15;g; s;%.[6E](\\..);\16;g; s;%.[7F](\\..);\17;g;
+ p}'