oct()
Treats leading characters of str as a string of octal digits (with an optional sign) and returns the corresponding number. Returns 0 if the conversion fails.
"123".oct #=> 83 "-377".oct #=> -255 "bad".oct #=> 0 "0377bad".oct #=> 255
static VALUE rb_str_oct(VALUE str) { return rb_str_to_inum(str, -8, FALSE); }