s|$|@ /\\ \n/__\\| : /1/{s/1@\| *$//gm;q} h s/.@// s/./a&/gm :1 s/.*/ & /gm s/a\(.*\)a/\1/gm //b1 s/^/%/ H g s/.@\|.%.*//g s/.*/&&/gm H x s/@.*%/@/ y/5432/4321/ b
Note that non-ascii characters in the above source code will be escaped (such as \x9f).