Process and Management

-------------------------------------------------------------------------------------------


pstree | less (shows the main process means parent process)

ps -aux | less (information abt the users and all the trminal)

inside this----

USER ---USERNAME
        the effective username of the task owner
PID ---- process id

%CPU --- cpu usage

%MEM ---- memory utilization

VSZ --- virtual set size of the process in KiB

RSS -- resident sent size (used size)the non-swapped physical memory that a task has used

TTY --- TTY information

STAT --- status

START -- starting time

TIME --- accumulated cpu time . the total cpu size the task has used since it started



top --( provides an ongoing look at processor activity in real time)

rpm --rebuilddb & --(to run the command in backend)

jobs  ( to see the backend process)

fg 1 ( to run the command in foreground, where 1 is the job number)

bg 1 ( for backgnd)

ctrl+z ( to stop the job running in ur terminal )


kill -l ( gives the information abt the signals)

// Check the singal types.

SIGHUP -
SIGINT-
SIGKILL-
SIGTERM-

kill -s <signal_no>  <PID>

kill -9 pid ( to kill any process)
 
    or

kill -STOP process name

killall xxxxxxxxxxxxxxxxxxxx



who --(information abt the login and the time of login)

whoami

who am i

pinky (same as who)

free

vmstat- (Virtual Memory Statistics)


iostat- (i/p o/p statistics for CPU & disks)
iostat -dNk 2 10


fuser -uc  To check which user/users have locked a file (using)
// useful for errors file device busy etc .. *


lsof List open files *
lsof -i tcp:111
lsof -i -n -P


nice -n <-20 - 19>  <cmd> *
renice -n <> -p <PID>

*= check for more options in man pages