CIGAL Reference Manual, Chapter 4 (Variables): sflags
usage: sflags = value
SFLAGS, an internally defined integer variable, controls options related to how the SKETCH command operates. The value of the SFLAGS parameter can be changed at any time and remains set until it is explicitly modified again. The meaning of the SFLAGS settings are summarized below. Combine levels by adding values.
Value (octal) Meaning: 1 1o Don't connect points if cursor has jumped; use MOVE 2 2o Paint region when cursor gets near starting point 4 4o Close loop when drawing gets near starting point 8 10o Measure length (& area) at end of each vector list 32 40o Don't sound bell while drawing 64 100o Use "rubberband" cursor for drawing 128 200o Allow cursor positions within menu region. The BACKSPACE key can be used to toggle MENUs on and off. 256 400o Connect points in pairs only 512 1000o Only one entry per button press 1024 2000o Don't erase text screen when starting SKETCH 2048 4000o Center text on reference point