- The reason you need a backslash before dollar sign is because
- this is a double quoted string in Tcl language, and without
- it the letter introduces a variable interpolation, which you
- do not want here.
+ A format specification with a '*' (asterisk) refers to *two* arguments
+ instead of one, hence the succeeding argument number is two higher
+ instead of one. So, a message like this
+
+ "%s ... %*i of %*i %s (%3i%%)"
+
+ is equivalent to
+
+ "%1$s ... %2$*i of %4$*i %6$s (%7$3i%%)"