by Jon Ripley, Richard Russell, January 2012
The FN_linenumber(!384) function returns the line number of the currently executing line of code as demonstrated below.
12345 PRINT FN_linenumber(!384) END DEF FN_linenumber(E%) LOCAL P% : P% = PAGE WHILE ?P% AND P% + ?P% < E% P% += ?P% : ENDWHILE = (P%?2*256+P%?1)
Always pass !384 as the parameter to FN_linenumber, this interpreter internal variable is the pointer to (or within) currently-executing statement.