Information about "PS" Command
On the display use can see the following process parameters:
USER :- username (only with u)
PID :- process ID - unique process identifier
TTY :- console with which the process is connected (? for daemons)
%CPU, %MEM :- current utilization of those resources
VSZ and RSS :- Virtual Segment Size and Resident Set Size (size of two parts of process - that which can be moved to virtual memory, and that which cannot)
STAT :- that is the status of the process: R – run-able S - sleeping, etc. as follows:
For BSD formats and when the stat keyword is used, additional characters may be displayed:
D :- Uninterruptible sleep (usually IO)
R :- Running or run-able (on run queue)
S :- Interruptible sleep (waiting for an event to complete)
T :- Stopped, either by a job control signal or because it is being traced.
W :- paging (not valid since the 2.6.xx kernel)
X :- dead (should never be seen)
Z :- Defunct ("zombie") process, terminated but not reaped by its parent.
< :- high-priority (not nice to other users)
N :- low-priority (nice to other users)
L :- has pages locked into memory (for real-time and custom IO)
s :- is a session leader
l :- is multi-threaded (using CLONE_THREAD, like NPTL pthreads do)
+ :- is in the foreground process group
START :- this is the time when the process has started to execute
TIME :- time used by the process
COMMAND :- the command line of the process</div>