[root@]# ps aux | less
USER       PID %CPU %MEM    VSZ   RSS TTY      STAT START   TIME COMMAND
root         1  0.0  0.0   2064   620 ?        Ss   Oct18   0:04 init [3]                 
root         2  0.0  0.0      0     0 ?        S<   Oct18   0:00 [migration/0]
root         3  0.0  0.0      0     0 ?        SN   Oct18   0:00 [ksoftirqd/0]
root         4  0.0  0.0      0     0 ?        S<   Oct18   0:00 [watchdog/0]
root         5  0.0  0.0      0     0 ?        S<   Oct18   0:00 [migration/1]
root         6  0.0  0.0      0     0 ?        SN   Oct18   0:00 [ksoftirqd/1]
root         7  0.0  0.0      0     0 ?        S<   Oct18   0:00 [watchdog/1]
root         8  0.0  0.0      0     0 ?        S<   Oct18   0:00 [migration/2]
root         9  0.0  0.0      0     0 ?        SN   Oct18   0:00 [ksoftirqd/2]
root        10  0.0  0.0      0     0 ?        S<   Oct18   0:00 [watchdog/2]
root        11  0.0  0.0      0     0 ?        S<   Oct18   0:00 [migration/3]
root        12  0.0  0.0      0     0 ?        SN   Oct18   0:00 [ksoftirqd/3]
root        13  0.0  0.0      0     0 ?        S<   Oct18   0:00 [watchdog/3]

how to view processes in linux********* simple selection *********  ********* selection by list *********
-A all processes                      -C by command name
-N negate selection                   -G by real group ID (supports names)
-a all w/ tty except session leaders  -U by real user ID (supports names)
-d all except session leaders         -g by session OR by effective group name
-e all processes                      -p by process ID
T  all processes on this terminal     -s processes in the sessions given
a  all w/ tty, including other users  -t by tty
g  OBSOLETE -- DO NOT USE             -u by effective user ID (supports names)
r  only running processes             U  processes for specified users
x  processes w/o controlling ttys     t  by tty
*********** output format **********  *********** long options ***********
-o,o user-defined  -f full            --Group --User --pid --cols --ppid
-j,j job control   s  signal          --group --user --sid --rows --info
-O,O preloaded -o  v  virtual memory  --cumulative --format --deselect
-l,l long          u  user-oriented   --sort --tty --forest --version
-F   extra full    X  registers       --heading --no-heading --context
                    ********* misc options *********
-V,V  show version      L  list format codes  f  ASCII art forest
-m,m,-L,-T,H  threads   S  children in sum    -y change -l format
-M,Z  security data     c  true command name  -c scheduling class
-w,w  wide output       n  numeric WCHAN,UID  -H process hierarchy

#ps -ef

Task: Use ps command

Type the following ps command to display all running process
# ps aux | less

Where,

• -A: select all processes
• a: select all processes on a terminal, including those of other users
• x: select processes without controlling ttys

Task: see every process on the system

# ps -A
# ps -e


Task: See every process except those running as root

# ps -U root -u root -N

Task: See process run by user vivek

# ps -u vivek