HP StorageWorks XPath OS 7.4.X Command Reference Guide (AA-RVHCC-TE, September 2005)

212 XPath OS CLI commands
When printing using the command keyword, a process that has exited and has a parent that has not yet
waited for the process (in other words, a zombie) is listed as <defunct>; a process that is blocked while
trying to exit is listed as <exiting>.
The ps command tries to locate the processes argument vector from the user area to print the command
name and arguments. This method is not reliable, because a process is allowed to destroy this information.
The ucomm (accounting) keyword always contains the real command name, contained in the process
structure p_comm field.
To indicate that the argument vector has been tampered with, ps appends the real command name to the
output within parentheses if the base name of the first argument in the argument vector does not match the
contents of the real command name. A special case is system processes and/or kernel threads that are
shown within parentheses, because they do not set their argument vector.
In addition, ps checks for the following two situations and does not append the real command name
parenthesized:
A The process has asked for random page replacement
VA_ANOM from madvise (for example, a LISP interpreter
in a garbage collection).
E The process is trying to exit.
K The process is a kernel thread or system process.
L The process has pages locked in core (for example, for
raw I/O).
N The process has reduced CPU scheduling priority.
S The process has asked for FIFO page replacement
(VA_SEQL, from madvise, for example, a large image
processing program using virtual memory to sequentially
address voluminous data).
s The process is a session leader.
V The process is suspended during vfork.
W The process is swapped out.
X The process is being traced or debugged.
tt An abbreviation for the path name of the controlling
terminal, if any. The abbreviation consists of the two
letters following /dev/tty, or for the console, co. This
is followed by a - if the process can no longer reach
that controlling terminal (for example, it has been
revoked).
wchan The event (an address in the system) on which a process
waits. When printed numerically, the initial part of the
address is trimmed off and the result is printed in
hexadecimal; for example, 0x80324000 prints as
324000.
-shellname The login process traditionally adds a - in front of the shell
name to indicate a login shell. The ps command will not append
the parenthesized command name if it matches the name in the
first argument of the argument vector, skipping the leading -.
daemonname: Daemon processes frequently report their current activity by
setting their name to be something such as daemonname:
current-activity. The ps command does not append the
parenthesized command name, if the string preceding the colon
(:) in the first argument of the argument vector matches the
command name.