Path: utzoo!news-server.csri.toronto.edu!cs.utexas.edu!uunet!shelby!agate!ziploc!eps
From: eps@toaster.SFSU.EDU (Eric P. Scott)
Newsgroups: comp.sys.next
Subject: table() call broken in 2.0?
Message-ID: <1392@toaster.SFSU.EDU>
Date: 4 Mar 91 05:34:30 GMT
Reply-To: eps@cs.SFSU.EDU (Eric P. Scott)
Organization: San Francisco State University
Lines: 58

In 1.0/1.0a you could read the process table using TBL_PROCINFO;
for example, here's a "mini-ps":

#include <stdio.h>
#include <sys/param.h>
#include <sys/table.h>
main() {
	register struct tbl_procinfo *pip;
	struct tbl_procinfo *pil;
	int npi;
	struct tbl_procinfo pi[256];	/* bad assumption! */

	npi=table(TBL_PROCINFO, 0, (char *)pi, sizeof pi/sizeof pi[0],
		sizeof pi[0]);
	if (npi<=0) {
		fputs("No processes??\n", stderr);
		exit(1);
	}
	pip=pi; pil= &pi[npi];
	fputs("      F  UID   PID  PPID  PGRP    TTYD COMMAND\n", stdout);
	do if (pip->pi_status!=PI_EMPTY) {
		printf("%7x%5d%6u%6u%6u ",
			pip->pi_flag, pip->pi_uid, pip->pi_pid, pip->pi_ppid,
			pip->pi_pgrp);
		if (pip->pi_ttyd==-1) fputs("      ?", stdout);
		else printf("%3d,%3d", major(pip->pi_ttyd),
			minor(pip->pi_ttyd));
		if (pip->pi_status!=PI_ACTIVE) fputs(" <defunct>", stdout);
		printf(" %.20s\n", pip->pi_comm);
	} while (++pip<pil);
	exit(0);
}

Which produces output like:

      F  UID   PID  PPID  PGRP    TTYD COMMAND
      3    0     0     0     0       ? kernel-task
      1    0     1     0     0       ? init
      1    0     2     0     2       ? mach_init
      1    0    55     1     0       ? nmserver
      1    0    48     1     0       ? syslogd

etc.

On 2.0 the table() call returns -1 with errno set to ESRCH.  If I
"cheat" and look at what was actually returned, I see:

      F  UID   PID  PPID  PGRP    TTYD COMMAND
      3    0     0     0     0       ? kernel idle
      1    0     1     0     0       ? init
      1    0     2     0     2   0,  0 mach_init
      1    0     3     0     0       ? kern_loader

and nothing else.  Is this totally broken under 2.0, or is there
an API change?  (Yes, I know this is undocumented, but I'd rather
not have to run set-gid kmem if I can avoid it.)

					-=EPS=-