Some inconsistencies have emerged during development
of support for these relatively new proc_t fields.
For example, a PROC_FILLCGROUP flag (via file2strvec)
could return NULL in cgroup whereas PROC_EDITCGRPCVT
(via fill_cgroup_cvt) *almost* guaranteed a return
address (as is true for PROC_EDITCMDLCVT and cmdline).
But even PROC_EDITCGRPCVT could return NULL if the
kernel version was less than 2.6.24. Then with NULL
ps would display a "-" while top would show "n/a".
And while unlikely, with the PROC_FILLSTATUS flag (via
status2proc) a NULL supgid address was theoretically
possible and both ps and top would then show "n/a".
This commit standardizes the following usage:
. PROC_FILLSTATUS (via status2proc)
guarantees a valid supgid address
representing either a true comma
delimited list or "-"
. PROC_FILLCGROUP plus
PROC_EDITCGRPCVT (via fill_cgroup_cvt)
guarantees a cgroup single vector
representing either a true control
group hierarchy or "-"
And as was true before, the following remains true:
PROC_FILLCOM or
PROC_FILLARG (via file2strvec)
may return a NULL cmdline pointer
. PROC_FILLCGROUP (via file2strvec)
may return a NULL cgroup pointer
. PROC_FILLCOM or
PROC_FILLARG plus
PROC_EDITCMDLCVT (via fill_cmdline_cvt)
guarantees a cmdline single vector
representing either a true command
line or a bracketed program name
. PROC_FILLSTATUS plus
PROC_FILLSUPGRP (via supgrps_from_supgids)
guarantees a valid supgrp address
representing either a true comma
delimited list or "-"
Signed-off-by: Jim Warner <james.warner@comcast.net>