Re: ps and AIX field descriptors

[Reco <recoverym4n@enotuniq.net>]

	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