%r on Decus C compiler

[scw%ucla-locus at cepu.UUCP]

From:  Steve Woods <cepu!scw at ucla-locus>


	RE:  Article-I.D.: fortune.1587

	I need to port some code (from DECUS C on the RT11), which uses
	the "%r" format in printf.  Of course, I've never heard of
	"%r", and I can't find it in K&R, or the documentation for V7
	or Sys III.  Does anyone know what it is, and (even better) how
	I can simulate it using standard printf formats?
					Thanks in advance...
	--

Looking in the decus c documentation I find: *NOTHING*

However looking in my mind I find %r (rad50);  Therefore I make the following

		   *****WILD GUESS*****

   The %r format will convert a short int (16 bits) to/from 3 alpha-numeric
   characters in the following manner:(source PDP-11 MACRO-11 Language
   Reference Manual {AA-5075B-TC} (pp 6-28))

   "Each character is translated into its Radix-50 equivalent, as indicated
   in the following table:
	Character		Radix-50 octal Equivalent

	(space)			0
	A-Z			1-32
	$			33
	.			34
	(undefined)		35
	0-9			36-47

    The Radix-50 equivalents for characters 1 through 3 (c1,c2,c3) are
    combined as follows:

	Radix-50 Value= ((c1*50+c2)*50+c3

    For example:

	Radix-50 Value of ABC = ((1*50+2)*50+3 = 3223 (8)"
[end of quote]

DEC uses Rad50 for filenames and other things (program names
[internally in their systems] and such like). I suspect that you can probably
junk the %r and substitute %o unless the program you are porting does file
lookups in an RT-11/Files-11 directory or some such.