From: Leslie Viljoen <leslieviljoen@...>
Date: 2006-07-29T18:40:31+09:00
Subject: Re: Bug in ruby printf/sprintf

On 7/29/06, Yukihiro Matsumoto <matz@ruby-lang.org> wrote:
> Hi,]
>
> In message "Re: Bug in ruby printf/sprintf"
>     on Sat, 29 Jul 2006 04:45:13 +0900, "paul.dlug@gmail.com" <paul.dlug@gmail.com> writes:
>
> |That's interesting. I just tried the same on linux (Gentoo) and you're
> |correct, printf in C behaves the same way there. In Mac OS X (10.4) and
> |FreeBSD (6.1) it does zero pad it as does perl on all platforms. I
> |wonder why I haven't hit this before and what the reason for the
> |difference is. Time to take a look at the doc's for the linux version.
>
> From Linux man page printf(3):
>
>        0      The  value  should be zero padded.  For d, i, o, u, x,
>               X, a, A, e, E, f, F, g, and G conversions, the converted
>               value is padded on the left with zeros rather than
>               blanks.  If the 0 and - flags both appear, the 0 flag is
>               ignored.  If a precision is given with a numeric
>               conversion (d, i, o, u, x, and X), the 0 flag is
>               ignored.  For other conversions, the behavior is
>               undefined.
>
> It's behavior is undefined, so that some fills with zeros and others
> just ignore.  Don't use zero with %s specifier if you want portable
> behavior.

So here's portable:
print "|#{str.rjust(10, "0")}|"

Sorry to insult everyone's intelligence!