Re: [HACKERS] backend now show status in 'ps'

> I believe, this won't work under Linux. I'm not 100% sure about it but from
> what I can remember Linux pass a copy of the original argv to the program
> and changing it doesn't change the argv strings shown by ps. You must zap
> the strings itself inside the page allocated for argv.
> I would suggest the following code which works fine also under linux, even
> with zero args.
>
> #ifdef linux
>     progname = argv[0];
>     /* Fill the argv buffer vith 0's, once during the initialization */
>     for (i=0; i<argc; argc++) {
>         memset(argv[i], 0, strlen(argv[i]));
>     }
> #endif

This is OK.  It will work.

>
>     /* Build status info */
>     sprintf(status, "%s ...", ...);
> #ifdef bsdi
>     argv[1] = status;
> #endif
> #ifdef linux
>     /* Print the original argv[0] + status info in the argv buffer */
>     sprintf(argv[0], "%s %s", progname, status);
> #endif

This may not work.  The problem is that there is no guarantee that there
enough string space in argv[0] to hold the new string value.  That is
why sendmail actually re-allocates/moves the argv[] strings to make
room, but such code is very ugly.

We can perform some tricks to make argv[0] larger by re-exec'ing the
postmaster, which we already do to make sure we have enough args, but
let's see what Linux people report.

> I would also suggest using only lowercase messages if possible. They don't
> hurt the eyes too much.

Yes, that would be nice, but I want to assign fixed string constants, so
they don't change, and currently I use the same strings that are
displayed as part of psql:

    test=> update test set x=2;
    UPDATE 2
        ^^^^^^

Didn't seem worth making another string for every command type, and
because it is a string constant, I can't lowercase it.

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