Re: [bug-gawk] gawk printf misunderstand

[Aharon Robbins]

Greetings. Re this:

> Date: Wed, 31 Oct 2012 16:44:17 +0600
> From: 145 Shkerin Egor (PROG) <address@hidden>
> To: address@hidden
> Subject: [bug-gawk] gawk printf misunderstand
>
> Hello,
> I have two different behavior in two neighbor versions,
> please clarify, what is wrong and how to make common solution.
>
> GNU Awk 3.1.5
> Copyright (C) 1989, 1991-2005 Free Software Foundation.
>
> echo "ff" | awk '{printf("% 4s\n", $1)}'
>   ff
>
> echo "ff" | awk '{printf("%04s\n", $1)}'
> 00ff
>
> It works exactly as I expect.
>
> In the same time:
>
> GNU Awk 3.1.8
> Copyright (C) 1989, 1991-2010 Free Software Foundation.
>
> echo "ff" | awk '{printf("% 4s\n", $1)}'
>   ff
>
> echo "ff" | awk '{printf("%04s\n", $1)}'
>   ff
>
> WHY not 00ff?
> -- 
> Egor Shkerin

Please see this from the NEWS file:

> Changes from 3.1.7 to 3.1.8
> ---------------------------
> 1. The zero flag no longer applies to %c and %s; apparently the standards
>    changed at some point.

So, the change was on purpose.  You can build the string yourself, which
I admit is more work, but will be portable.

        function zero_prefix(string, len)
        {
                while (length(string) < len)
                        string = "0" string
                return string
        }

Thanks,

Arnold