From: Warren Brown <wkb@...>
Date: 2003-02-13T03:25:45+09:00
Subject: sprintf() bug

    I have run across a discrepancy between the documentation and ruby
1.6.8.  According to the pickaxe book, the flag character '0' changes
padding from spaces (' ') to zeros ('0').  This works for numbers, but does
not work for stings:

irb(main):001:0> sprintf "%05d,%05s", 1, '1'
=> "00001,    1"

    A simple fix (from the 1.6.8 version) would be:
--------------------------------
--- sprintf.c.old       Thu Dec 12 03:16:44 2002
+++ sprintf.c.new       Wed Feb 12 11:12:07 2003
@@ -287,8 +287,9 @@
                        CHECK(width);
                        width -= len;
                        if (!(flags&FMINUS)) {
+                           char c = (flags & FZERO) ? '0' : ' ';
                            while (width--) {
-                               buf[blen++] = ' ';
+                               buf[blen++] = c;
                            }
                        }
--------------------------------

    To get around this problem, I ended up using the combination
mystring.rjust(5).tr(' ','0').  This worked for me since my string was
guaranteed not to have any spaces, but if that were not the case, this would
get messy.

    It occurred to me that String#ljust and String#rjust really seem like
they should have an optional second parameter that defaults to ' ', but
could be any character (or any string?).  Anyone else think this is a good
idea?

    - Warren Brown