Re: ps and AIX field descriptors

[Andreas Leha <andreas.leha@med.uni-goettingen.de>]

Reco <recoverym4n@enotuniq.net> writes:

> 	Hi.
>
> On Fri, Feb 17, 2023 at 07:46:23AM +0100, Andreas Leha wrote:
>> Now my question: How can I restore the previous behaviour that allowed
>> other than whitespace separators between fields?
>
> diff -purw procps-3.3.17/ps/sortformat.c procps-4.0.2/src/ps/sortformat.c
> shows me that:
>
> @@ -128,22 +127,24 @@ static const char *aix_format_parse(sf_n
>    items = 0;
>    walk = sfn->sf;
>    /* state machine */ {
> -  int c;
> +  int c = *walk++;
>    initial:
> -    c = *walk++;
>      if(c=='%')    goto get_desc;
>      if(!c)        goto looks_ok;
>    /* get_text: */
>      items++;
> -  get_more_text:
> +  get_more:
>      c = *walk++;
>      if(c=='%')    goto get_desc;
> -    if(c)         goto get_more_text;
> +    if(c==' ')    goto get_more;
> +    if(c)         goto aix_oops;
>      goto looks_ok;
>    get_desc:
>      items++;
>      c = *walk++;
> -    if(c)         goto initial;
> +    if(c&&c!=' ') goto initial;
> +    return _("missing AIX field descriptor");
> +  aix_oops:
>      return _("improper AIX field descriptor");
>    looks_ok:
>      ;
>
> If you look at "get_more" label, you'll notice that "old" version of
> procps (bullseye's) checked for any character after "%<char>" block.
> "New" one (bookworm's) explicitly checks for space, and goes to
> "aix_oops" in any other case.
>
> And there is no #ifdefs, no environment variable checks, no options
> etc.
>
>
> So, to answer your question - currently the only way to restore the
> behaviour you want is to patch procps and rebuild it.
>
> Reco


Dear Reco,

Thanks for the fast and accurate answer!  What a shame for this change...

Best,
Andreas