0005034: PS: Commandline options to PS cause major problems from scripts

(0011564)
vda
09-17-08 18:09

Actually, ps has WILDLY different switches in different Unixes, to the point that POSIX had hard time finding a common subset.

It proved impossible, thus many switches are not documented in POSIX. This is what _is_ documented according to my POSIX manpage:

PS(P) POSIX Programmer's Manual PS(P)
NAME
       ps - report process status
SYNOPSIS
       ps [-aA][-defl][-G grouplist][-o format]...[-p proclist][-t termlist]
       [-U userlist][-g grouplist][-n namelist][-u userlist]
       -a Write information for all processes associated with terminals.
              Implementations may omit session leaders from this list.
       -A Write information for all processes.
       -d Write information for all processes, except session leaders.
       -e Write information for all processes. (Equivalent to -A.)
       -f Generate a full listing. (See the STDOUT section for the con-
              tents of a full listing.)
...
       -u userlist
              Write information for processes whose user ID numbers or login
              names are given in userlist.
...

As you see, "ps -aux" is not POSIX-compliant, even "ps -au" is not.

But POSIX does have a nice way to output exactly those columnts you want - it's "-o format" option. That is the way to use ps portably.

If you have cases where busybox ps contradicts POSIX/SUSv3, that is a real problem.

(0011574)
path0s
09-17-08 19:59

Well, I'm on a uclibc/busybox based ARM install (western digital mybookworld) that used to have many commandline switches to it's old busybox PS command. I upgraded busybox to 1.12 and now quite a few of the scripts are broke because PS no longer supports any switch besides 'w' and throws an error:

[root@MyBookWorld ~]# ps -e
ps: illegal option -- e
BusyBox v1.12.0 (2008-09-01 00:36:05 CDT) multi-call binary

Usage: ps

Report process status

Options:
w Wide output

[root@MyBookWorld ~]#

(0011634)
vda
09-18-08 15:58

ps.c has "big" implementation conditionalized on CONFIG_DESKTOP=y, try it.
Supported options: -ZaAdefl -o col1,col2,col3=header

(0011644)
path0s
09-18-08 19:31

Ahh very good, thank you. Had no idea that the desktop option would affect small things such as PS.. Sorry to of filed a bug about this, I looked as much as I could.. I swear :)

Consider this closed.

Issue History
Date Modified	Username	Field	Change
09-17-08 12:28	path0s	New Issue
09-17-08 12:28	path0s	Status	new => assigned
09-17-08 12:28	path0s	Assigned To	=> BusyBox
09-17-08 18:09	vda	Note Added: 0011564
09-17-08 19:59	path0s	Note Added: 0011574
09-18-08 15:58	vda	Note Added: 0011634
09-18-08 19:31	path0s	Note Added: 0011644
09-28-08 16:23	vda	Status	assigned => closed
09-28-08 16:23	vda	Resolution	open => no change required

Notes
(0011564) vda 09-17-08 18:09	Actually, ps has WILDLY different switches in different Unixes, to the point that POSIX had hard time finding a common subset. It proved impossible, thus many switches are not documented in POSIX. This is what _is_ documented according to my POSIX manpage: PS(P) POSIX Programmer's Manual PS(P) NAME ps - report process status SYNOPSIS ps [-aA][-defl][-G grouplist][-o format]...[-p proclist][-t termlist] [-U userlist][-g grouplist][-n namelist][-u userlist] -a Write information for all processes associated with terminals. Implementations may omit session leaders from this list. -A Write information for all processes. -d Write information for all processes, except session leaders. -e Write information for all processes. (Equivalent to -A.) -f Generate a full listing. (See the STDOUT section for the con- tents of a full listing.) ... -u userlist Write information for processes whose user ID numbers or login names are given in userlist. ... As you see, "ps -aux" is not POSIX-compliant, even "ps -au" is not. But POSIX does have a nice way to output exactly those columnts you want - it's "-o format" option. That is the way to use ps portably. If you have cases where busybox ps contradicts POSIX/SUSv3, that is a real problem.

(0011574) path0s 09-17-08 19:59	Well, I'm on a uclibc/busybox based ARM install (western digital mybookworld) that used to have many commandline switches to it's old busybox PS command. I upgraded busybox to 1.12 and now quite a few of the scripts are broke because PS no longer supports any switch besides 'w' and throws an error: [root@MyBookWorld ~]# ps -e ps: illegal option -- e BusyBox v1.12.0 (2008-09-01 00:36:05 CDT) multi-call binary Usage: ps Report process status Options: w Wide output [root@MyBookWorld ~]#

(0011634) vda 09-18-08 15:58	ps.c has "big" implementation conditionalized on CONFIG_DESKTOP=y, try it. Supported options: -ZaAdefl -o col1,col2,col3=header

(0011644) path0s 09-18-08 19:31	Ahh very good, thank you. Had no idea that the desktop option would affect small things such as PS.. Sorry to of filed a bug about this, I looked as much as I could.. I swear :) Consider this closed.

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