top    [ options ]

-h

Print help and then exit.

-b : Batch-mode operation

Starts top in 'Batch' mode, which could be useful for sending output from top to other programs or to a file. In this mode, top will not accept input and runs until the iterations limit you've set with the '-n' Shell option or until killed.

-d : Delay-time interval as: -d ss.tt (secs.tenths)

Specifies the delay between screen updates, and overrides the corresponding value in one's personal configuration file or the startup default.  Later this can be changed with the 'd' or 's' interactive commands.

-H : Threads-mode operation

Instructs top to display individual threads.  Without this Shell option a summation of all threads in each process is shown. Later this can be changed with the 'H' interactive command.

-p : Monitor-PIDs mode as: -pN1 -pN2 ... or -pN1,N2,N3 ...

Monitor only processes with specified process IDs. This option can be given up to 20 times, or you can provide a comma delimited list with up to 20 pids. Co-mingling both approaches is permitted.

-u | -U : User-filter-mode as: -u | -U number or name

Display only processes with a user id or user name matching that given.  The '-u' option matches on effective user whereas the '-U' option matches on any user (real, effective, saved, or filesystem). The 'p', 'u' and 'U' Shell options are mutually exclusive.

pi@raspberrypi ~ $ top

%CPU

us

사용자 application에 할당된 량

sy

시스템 application에 할당된 량

ni

nice된 process에 할당된 량

id

Idle

wa

I/O waiting process에 할당된 량

hi

hardware interrupt waiting process에 할당된 량

si

software interrupt waiting process에 할당된 량

st

hypervisor에 뺏긴 량

process 목록

PID

process id

PPID

parent process의 process id

Command

process에서 처리하는 명령 또는 프로그램

PR

process의 우선순위

VIRT

사용하는 가상메모리(virtual memory)의 양

RES

사용하고 있는 상주메모리(resident memory)의 양

SHR

사용하고 있는 공유메모리(shared memory)의 양

S

process 상태

TIME

Task 시작 이후 사용한 CPU 시간

free    [ options ]

--help

Print help.

-k, --kilo

Display the amount of memory in kilobytes.  This is the default.

-m, --mega

Display the amount of memory in megabytes

pi@raspberrypi ~ $ free

             total       used       free     shared    buffers     cached

Mem:        380780     359936      20844          0      27560     187772

-/+ buffers/cache:     144604     236176

Swap:       102396          0     102396

ps    [ options ]

r

Restrict the selection to only running processes.

-N, --deselect

Select all processes except those that fulfill the specified conditions (negates the selection).   

-e

Select all processes.  Identical to -A.

-a

Select all processes except both session leaders (see getsid(2)) and processes not associated with a terminal.

-C cmdlist

Select by command name.  This selects the processes whose executable name is given in cmdlist.

--pid pidlist

Select by process ID.  Identical to -p and p.

--ppid pidlist

Select by parent process ID.  This selects the processes with a parent process ID in pidlist.  That is, it selects processes that are children of those listed in pidlist.

-u userlist

Select by effective user ID (EUID) or name.  This selects the processes

whose effective user name or ID is in userlist. The effective user ID describes the user whose file access permissions are used by the process (see geteuid(2)).  Identical to U and --user.

-t ttylist

Select by tty.  This selects the processes associated with the terminals given in ttylist.  Terminals (ttys, or screens for text output) can be specified in several forms: /dev/ttyS1, ttyS1, S1.  A plain "-" may be used to select processes not attached to any terminal.

-f

Do full-format listing. This option can be combined with many other UNIX-style options to add additional columns. It also causes the command arguments to be printed.  When used with -L, the NLWP (number of threads) and LWP (thread ID) columns will be added.  See the c option, the format keyword args, and the format keyword comm.

pi@raspberrypi ~ $ ps

  PID TTY          TIME CMD

 5752 pts/0    00:00:01 bash

 6135 pts/0    00:00:00 ps

pi@raspberrypi ~ $ ps -af

UID        PID  PPID  C STIME TTY          TIME CMD

pi        3481  3402  0 May28 tty1     00:00:01 -bash

pi        3507  3481  0 May28 tty1     00:00:00 /bin/sh /usr/bin/startx

pi        3524  3507  0 May28 tty1     00:00:00 xinit /etc/X11/xinit/xinitrc -- /etc/X11/xin

pi        3529  3524  0 May28 tty1     00:00:00 /usr/bin/ck-launch-session /usr/bin/dbus-lau

pi        3629  3529  0 May28 tty1     00:00:00 /usr/bin/lxsession -s LXDE-pi -e LXDE

pi        3632     1  0 May28 tty1     00:00:00 /usr/bin/dbus-launch --exit-with-session x-s

pi        3639  3629  0 May28 tty1     00:00:00 openbox --config-file /home/pi/.config/openb

pi        3641  3629  0 May28 tty1     00:03:54 lxpanel --profile LXDE-pi

pi        3648     1  0 May28 tty1     00:00:00 /usr/lib/arm-linux-gnueabihf/lxpolkit

pi        3672     1  0 May28 tty1     00:00:05 /usr/lib/arm-linux-gnueabihf/libmenu-cache1/

pi        5349  3629  0 09:11 tty1     00:00:01 pcmanfm --desktop --profile LXDE-pi

pi        6139  5752  0 13:42 pts/0    00:00:00 ps -af

항목

설명

PID

process id

PPID

parent process의 process id

C

process의 CPU 사용량

STIME

process시작시간

TTY

process가 연결된 terminal

UID

user id

TIME

Task 시작 이후 사용한 CPU 시간

CMD

process를 실행한 명령과 argument

pi@raspberrypi ~ $ ps -ef | grep motion

motion    6835     1  1 19:07 ?        00:01:19 /usr/bin/motion

pi        7053  6586  0 20:16 pts/0    00:00:00 grep --color=auto motion