Q1 :/dev/null Q2 -A

UNIX for Advanced & Expert Users
1

Hi,
Q1-What does
nroff -ms > /dev/null
Q2- What does mean -A under STAT column :
ps aux |head -20
UTIL PID %CPU %MEM SZ RSS TTY STAT STIME TIME COMMAND
root 516 93,0 0,0 12 12 - A 04 nov 3906:51 wait

Thank you.

2

/dev/null is the bit bucket - an infinite data sink - all bit go in nothing ever comes out.
> /dev/null just prevents output from nroff from appearing on the tty.

3

To answer your second question, I did a little googling:
I got this from the Linux man page:

If you look up the PROCESS STATE CODES, this is what you get:

The state 'A' does not appear.

--EDIT--
Even the HP-UX man page does not list a process state 'A'. HP ps does not have a STAT column, it has S instead.
S (l) The state of the process:
0 non-existent;
S sleeping;
W waiting;
R running;
I intermediate;
Z terminated;
T stopped;
X growing.
--/EDIT--
--EDIT--
Ditto with Sun
S (l)
The state of the process:
O
Process is running on a processor.
S
Sleeping: process is waiting for an event to complete.
R
Runnable: process is on run queue.
Z
Zombie state: process terminated and parent not waiting.
T
Process is stopped, either by a job control signal or because it is being traced.
--/EDIT--

4

I got your process state A on the AIX man page!

5

Manymany thanks to all.