Linux下PS命令詳解

要對系統中進程進行監測控制，查看狀態，內存，CPU的使用狀況，使用命令：/bin/ps

（1）         ps ：是顯示瞬間進程的狀態，並不動態連續；

（2）         top：若是想對進程運行時間監控，應該用 top 命令；

（3）         kill 用於殺死進程或者給進程發送信號；

（4）        查看文章最後的man手冊，能夠查看ps的每項輸出的含義，to find: STANDARD FORMAT SPECIFIERS

===================================ps 的參數說明=============================

l 長格式輸出；

u 按用戶名和啓動時間的順序來顯示進程；

j 用任務格式來顯示進程；

f 用樹形格式來顯示進程；

a 顯示全部用戶的全部進程（包括其它用戶）；

x 顯示無控制終端的進程；

r 顯示運行中的進程；

ww 避免詳細參數被截斷；

-A 列出全部的進程
-w 顯示加寬能夠顯示較多的資訊
-au 顯示較詳細的資訊
-aux 顯示全部包含其餘使用者的進程

-e 顯示全部進程,環境變量
-f 全格式
-h 不顯示標題
-l 長格式
-w 寬輸出
a   顯示終端上地全部進程,包括其餘用戶地進程
r   只顯示正在運行地進程
x   顯示沒有控制終端地進程

咱們經常使用的選項是組合是 aux 或 lax，還有參數 f 的應用。
pids 只列出進程標識符,之間運用逗號分隔.該進程列表必須在命令行參數地最後一個選項後面緊接着給出,中間不能插入空格.好比：ps -f1,4,5 顯示的是進程ID爲1,4,5的進程

下介紹長命令行選項,這些選項都運用「--」開頭：
--sort X[+|-] key [,[+|-] key [,…]] 從SORT KEYS段中選一個多字母鍵.「+」字符是可選地,由於默認地方向就是按數字升序或者詞典順序，「-」字符是逆序排序（即降序）.

好比： ps -jax -sort=uid,-ppid,+pid.
--help 顯示幫助信息.
--version 顯示該命令地版本信息.

在前面地選項說明中提到了排序鍵,接下來對排序鍵做進一步說明.須要注意地是排序中運用地值是ps運用地內部值,並不是僅用於某些輸出格式地僞值.排序鍵列表見下表.

============排序鍵列表==========================
c cmd   可執行地簡單名稱 
C cmdline   完整命令行 
f flags   長模式標誌 
g pgrp   進程地組ID 
G tpgid   控制tty進程組ID 
j cutime   累計用戶時間 
J cstime   累計系統時間 
k utime   用戶時間 
K stime   系統時間 
m min_flt   次要頁錯誤地數量 
M maj_flt   重點頁錯誤地數量 
n cmin_flt 累計次要頁錯誤 
N cmaj_flt 累計重點頁錯誤 
o session   對話ID 
p pid   進程ID 
P ppid   父進程ID 
r rss   駐留大小 
R resident 駐留頁 
s size   內存大小(千字節) 
S share   共享頁地數量 
t tty   tty次要設備號 
T start_time 進程啓動地時間 
U uid   UID
u user   用戶名
v vsize   總地虛擬內存數量(字節) 
y priority 內核調度優先級
========================================ps aux 或 lax 輸出的解釋=========================

二、ps aux 或 lax 輸出的解釋

au(x) 輸出格式 : 
USER PID %CPU %MEM VSZ RSS TTY STAT START TIME COMMAND

USER: 進程全部者
PID: 進程ID

%CPU: 佔用的 CPU 使用率
%MEM: 佔用的內存使用率
VSZ: 佔用的虛擬內存大小
RSS: 佔用的內存大小

TTY: 終端的次要裝置號碼 (minor device number of tty)

STAT: 進程狀態:

START: 啓動進程的時間； 
TIME: 進程消耗CPU的時間；
COMMAND:命令的名稱和參數；

=========================================進程STAT狀態==================================

D 沒法中斷的休眠狀態（一般 IO 的進程）； 
R 正在運行，在可中斷隊列中； 
S 處於休眠狀態，靜止狀態； 
T 中止或被追蹤，暫停執行； 
W 進入內存交換（從內核2.6開始無效）； 
X 死掉的進程； 
Z 殭屍進程不存在但暫時沒法消除；

W: 沒有足夠的記憶體分頁可分配
WCHAN 正在等待的進程資源；

<: 高優先級進程
N: 低優先序進程
L: 有記憶體分頁分配並鎖在記憶體內 (即時系統或捱A I/O)，即,有些頁被鎖進內存

s 進程的領導者（在它之下有子進程）； 
l 多進程的（使用 CLONE_THREAD, 相似 NPTL pthreads）； 
+ 位於後臺的進程組；

========================================kill 終止進程================================

kill 終止進程

有十幾種控制進程的方法，下面是一些經常使用的方法:

kill -STOP [pid] 
發送SIGSTOP (17,19,23)中止一個進程，而並不消滅這個進程。

kill -CONT [pid] 
發送SIGCONT (19,18,25)從新開始一箇中止的進程。

kill -KILL [pid] 
發送SIGKILL (9)強迫進程當即中止，而且不實施清理操做。

kill -9 -1 
終止你擁有的所有進程。

SIGKILL 和 SIGSTOP 信號不能被捕捉、封鎖或者忽略，可是，其它的信號能夠。因此這是你的終極武器。

==================================================範例==============================

$ ps
PID TTY TIME COMMAND
5800 ttyp0 00:00:00 bash
5835 ttyp0 00:00:00 ps
能夠看到,顯示地項目共分爲四項,依次爲PID(進程ID)、TTY(終端名稱)、TIME(進程執行時 間)、COMMAND(該進程地命令行輸入).

能夠運用u選項來查看進程全部者及其餘少量詳細信息,以下所示：
$ ps u
USER PID %CPU %MEM USZ RSS TTY STAT START TIME COMMAND
test 5800 0.0 0.4 1892 1040 ttyp0 S Nov27 0:00 -bash
test 5836 0.0 0.3 2528 856 ttyp0 R Nov27 0:00 ps u

在bash進程前面有條橫線,意味着該進程即是用戶地登陸shell,因此對於一個登陸用戶來講帶短橫線地進程只有一個.還能夠看 到%CPU、%MEM兩個選項,前者指該進程佔用地CPU時間

和總時間地百分比;後者指該進程佔用地內存和總內存地百分比.
在這種狀況下看到了全部控制終端地進程;固然對於其餘那些沒有控制終端地進程 仍是沒有觀察到,因此這時就須要運用x選項.運用x選項能夠觀察到全部地進程狀況.

1)ps a 顯示現行終端機下的全部程序，包括其餘用戶的程序。
2)ps -A 顯示全部程序。
3)ps c 列出程序時，顯示每一個程序真正的指令名稱，而不包含路徑，參數或常駐服務的標示。
4)ps -e 此參數的效果和指定"A"參數相同。
5)ps e 列出程序時，顯示每一個程序所使用的環境變量。
6)ps f 用ASCII字符顯示樹狀結構，表達程序間的相互關係。
7)ps -H 顯示樹狀結構，表示程序間的相互關係。
8)ps -N 顯示全部的程序，除了執行ps指令終端機下的程序以外。
9)ps s 採用程序信號的格式顯示程序情況。
10)ps S 列出程序時，包括已中斷的子程序資料。
11)ps -t<終端機編號> 　指定終端機編號，並列出屬於該終端機的程序的情況。
12)ps u 　以用戶爲主的格式來顯示程序情況。
13)ps x 　顯示全部程序，不以終端機來區分。

　最經常使用的方法是ps -aux,而後再用管道符號導向到grep去查找特定的進程,而後再對特定的進程進行操做。

==================================================

luther@gliethttp:~$ ps --help
********* 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
luther@gliethttp:~$ man ps

EXAMPLES To see every process on the system using standard syntax:    ps -e    ps -ef    ps -eF    ps -ely To see every process on the system using BSD syntax:    ps ax    ps axu To print a process tree:    ps -ejH    ps axjf To get info about threads:    ps -eLf    ps axms To get security info:    ps -eo euser,ruser,suser,fuser,f,comm,label    ps axZ    ps -eM To see every process running as root (real & effective ID) in user format:    ps -U root -u root u To see every process with a user-defined format:    ps -eo pid,tid,class,rtprio,ni,pri,psr,pcpu,stat,wchan:14,comm    ps axo stat,euid,ruid,tty,tpgid,sess,pgrp,ppid,pid,pcpu,comm    ps -eopid,tt,user,fname,tmout,f,wchan Print only the process IDs of syslogd:    ps -C syslogd -o pid= Print only the name of PID 42:    ps -p 42 -o comm= SIMPLE PROCESS SELECTION -A   Select all processes. Identical to -e. -N   Select all processes except those that fulfill the      specified conditions. (negates the selection) Identical      to --deselect. T    Select all processes associated with this terminal.      Identical to the t option without any argument. -a   Select all processes except both session leaders (see      getsid(2)) and processes not associated with a      terminal. a    Lift the BSD-style "only yourself" restriction, which      is imposed upon the set of all processes when some      BSD-style (without "-") options are used or when the ps      personality setting is BSD-like. The set of processes      selected in this manner is in addition to the set of      processes selected by other means. An alternate      description is that this option causes ps to list all      processes with a terminal (tty), or to list all      processes when used together with the x option. -d   Select all processes except session leaders. -e   Select all processes. Identical to -A. g    Really all, even session leaders. This flag is obsolete      and may be discontinued in a future release. It is      normally implied by the a flag, and is only useful when      operating in the sunos4 personality. r    Restrict the selection to only running processes. x    Lift the BSD-style "must have a tty" restriction, which      is imposed upon the set of all processes when some      BSD-style (without "-") options are used or when the ps      personality setting is BSD-like. The set of processes      selected in this manner is in addition to the set of      processes selected by other means. An alternate      description is that this option causes ps to list all      processes owned by you (same EUID as ps), or to list      all processes when used together with the a option. PROCESS SELECTION BY LIST These options accept a single argument in the form of a blank-separated or comma-separated list. They can be used multiple times. For example: ps -p "1 2" -p 3,4 -C cmdlist      Select by command name.                 This selects the processes whose executable name is                 given in cmdlist. -G grplist      Select by real group ID (RGID) or name.                 This selects the processes whose real group name or ID                 is in the grplist list. The real group ID identifies                 the group of the user who created the process, see                 getgid(2). 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. -U userlist     select by real user ID (RUID) or name.                 It selects the processes whose real user name or ID is                 in the userlist list. The real user ID identifies the                 user who created the process, see getuid(2). -g grplist      Select by session OR by effective group name.                 Selection by session is specified by many standards,                 but selection by effective group is the logical                 behavior that several other operating systems use. This                 ps will select by session when the list is completely                 numeric (as sessions are). Group ID numbers will work                 only when some group names are also specified. See the                 -s and --group options. p pidlist       Select by process ID. Identical to -p and --pid. -p pidlist      Select by PID.                 This selects the processes whose process ID numbers                 appear in pidlist. Identical to p and --pid. -s sesslist     Select by session ID.                 This selects the processes with a session ID specified                 in sesslist. t ttylist       Select by tty. Nearly identical to -t and --tty, but                 can also be used with an empty ttylist to indicate the                 terminal associated with ps. Using the T option is                 considered cleaner than using T with an empty ttylist. -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. -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. --Group grplist Select by real group ID (RGID) or name. Identical to                 -G. --User userlist Select by real user ID (RUID) or name. Identical to -U. --group grplist Select by effective group ID (EGID) or name.                 This selects the processes whose effective group name                 or ID is in grouplist. The effective group ID describes                 the group whose file access permissions are used by the                 process (see geteuid(2)). The -g option is often an                 alternative to --group. --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. --sid sesslist  Select by session ID. Identical to -s. --tty ttylist   Select by terminal. Identical to -t and t. --user userlist Select by effective user ID (EUID) or name. Identical                 to -u and U. -123            Identical to --sid 123. 123             Identical to --pid 123. OUTPUT FORMAT CONTROL These options are used to choose the information displayed by ps. The output may differ by personality. -F              extra full format. See the -f option, which -F implies. -O format       is like -o, but preloaded with some default columns.                 Identical to -o pid,format,state,tname,time,command or                 -o pid,format,tname,time,cmd, see -o below. O format        is preloaded o (overloaded).                 The BSD O option can act like -O (user-defined output                 format with some common fields predefined) or can be                 used to specify sort order. Heuristics are used to                 determine the behavior of this option. To ensure that                 the desired behavior is obtained (sorting or                 formatting), specify the option in some other way (e.g.                 with -O or --sort). When used as a formatting option,                 it is identical to -O, with the BSD personality. -M              Add a column of security data. Identical to Z.                 (for SE Linux) X               Register format. Z               Add a column of security data. Identical to -M.                 (for SE Linux) -c              Show different scheduler information for the -l option. -f              does 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. j               BSD job control format. -j              jobs format l               display BSD long format. -l              long format. The -y option is often useful with this. o format        specify user-defined format. Identical to -o and                 --format. -o format       user-defined format.                 format is a single argument in the form of a                 blank-separated or comma-separated list, which offers a                 way to specify individual output columns. The                 recognized keywords are described in the STANDARD                 FORMAT SPECIFIERS section below. Headers may be renamed                 (ps -o pid,ruser=RealUser -o comm=Command) as desired.                 If all column headers are empty (ps -o pid= -o comm=)                 then the header line will not be output. Column width                 will increase as needed for wide headers; this may be                 used to widen up columns such as WCHAN                 (ps -o pid,wchan=WIDE-WCHAN-COLUMN -o comm). Explicit                 width control (ps opid,wchan:42,cmd) is offered too.                 The behavior of ps -o pid=X,comm=Y varies with                 personality; output may be one column named "X,comm=Y"                 or two columns named "X" and "Y". Use multiple -o                 options when in doubt. Use the PS_FORMAT environment                 variable to specify a default as desired; DefSysV and                 DefBSD are macros that may be used to choose the                 default UNIX or BSD columns. s               display signal format u               display user-oriented format v               display virtual memory format -y              Do not show flags; show rss in place of addr. This                 option can only be used with -l. --format format user-defined format. Identical to -o and o. --context       Display security context format. (for SE Linux) OUTPUT MODIFIERS -H              show process hierarchy (forest) N namelist      Specify namelist file. Identical to -n, see -n above. O order         Sorting order. (overloaded)                 The BSD O option can act like -O (user-defined output                 format with some common fields predefined) or can be                 used to specify sort order. Heuristics are used to                 determine the behavior of this option. To ensure that                 the desired behavior is obtained (sorting or                 formatting), specify the option in some other way (e.g.                 with -O or --sort).                 For sorting, obsolete BSD O option syntax is                 O[+|-]k1[,[+|-]k2[,...]]. It orders the processes                 listing according to the multilevel sort specified by                 the sequence of one-letter short keys k1, k2, ...                 described in the OBSOLETE SORT KEYS section below.                 The "+" is currently optional, merely re-iterating the                 default direction on a key, but may help to distinguish                 an O sort from an O format. The "-" reverses direction                 only on the key it precedes. S               Sum up some information, such as CPU usage, from dead                 child processes into their parent. This is useful for                 examining a system where a parent process repeatedly                 forks off short-lived children to do work. c               Show the true command name. This is derived from the                 name of the executable file, rather than from the argv                 value. Command arguments and any modifications to them                 are thus not shown. This option effectively turns the                 args format keyword into the comm format keyword; it is                 useful with the -f format option and with the various                 BSD-style format options, which all normally display                 the command arguments. See the -f option, the format                 keyword args, and the format keyword comm. e               Show the environment after the command. f               ASCII-art process hierarchy (forest) h               No header. (or, one header per screen in the BSD                 personality)                 The h option is problematic. Standard BSD ps uses this                 option to print a header on each page of output, but                 older Linux ps uses this option to totally disable the                 header. This version of ps follows the Linux usage of                 not printing the header unless the BSD personality has                 been selected, in which case it prints a header on each                 page of output. Regardless of the current personality,                 you can use the long options --headers and --no-headers                 to enable printing headers each page or disable headers                 entirely, respectively. k spec          specify sorting order. Sorting syntax is                 [+|-]key[,[+|-]key[,...]] Choose a multi-letter key                 from the STANDARD FORMAT SPECIFIERS section. The "+" is                 optional since default direction is increasing                 numerical or lexicographic order. Identical to --sort.                 Examples:                 ps jaxkuid,-ppid,+pid                 ps axk comm o comm,args                 ps kstart_time -ef -n namelist     set namelist file. Identical to N.                 The namelist file is needed for a proper WCHAN display,                 and must match the current Linux kernel exactly for                 correct output. Without this option, the default search                 path for the namelist is:                      $PS_SYSMAP                      $PS_SYSTEM_MAP                      /proc/*/wchan                      /boot/System.map-`uname -r`                      /boot/System.map                      /lib/modules/`uname -r`/System.map                      /usr/src/linux/System.map                      /System.map n               Numeric output for WCHAN and USER. (including all types                 of UID and GID) -w              Wide output. Use this option twice for unlimited width. w               Wide output. Use this option twice for unlimited width. --cols n        set screen width --columns n     set screen width --cumulative    include some dead child process data (as a sum with the                 parent) --forest        ASCII art process tree --headers       repeat header lines, one per page of output --no-headers    print no header line at all. --no-heading is an alias                 for this option. --lines n       set screen height --rows n        set screen height --sort spec     specify sorting order. Sorting syntax is                 [+|-]key[,[+|-]key[,...]] Choose a multi-letter key                 from the STANDARD FORMAT SPECIFIERS section. The "+" is                 optional since default direction is increasing                 numerical or lexicographic order. Identical to k. For                 example: ps jax --sort=uid,-ppid,+pid --width n       set screen width THREAD DISPLAY        H               Show threads as if they were processes        -L              Show threads, possibly with LWP and NLWP columns        -T              Show threads, possibly with SPID column        m               Show threads after processes        -m              Show threads after processes OTHER INFORMATION        L               List all format specifiers.        -V              Print the procps version.        V               Print the procps version.        --help          Print a help message.        --info          Print debugging info.        --version       Print the procps version. NOTES        This ps works by reading the virtual files in /proc. This ps does not        need to be setuid kmem or have any privileges to run. Do not give this        ps any special permissions.        This ps needs access to namelist data for proper WCHAN display. For        kernels prior to 2.6, the System.map file must be installed.        CPU usage is currently expressed as the percentage of time spent        running during the entire lifetime of a process. This is not ideal,        and it does not conform to the standards that ps otherwise conforms to.        CPU usage is unlikely to add up to exactly 100%.        The SIZE and RSS fields don't count some parts of a process including        the page tables, kernel stack, struct thread_info, and struct        task_struct. This is usually at least 20 KiB of memory that is always        resident. SIZE is the virtual size of the process (code+data+stack).        Processes marked are dead processes (so-called "zombies")        that remain because their parent has not destroyed them properly. These        processes will be destroyed by init(8) if the parent process exits. PROCESS FLAGS        The sum of these values is displayed in the "F" column, which is        provided by the flags output specifier.        1    forked but didn't exec        4    used super-user privileges PROCESS STATE CODES        Here are the different values that the s, stat and state output        specifiers (header "STAT" or "S") will display to describe the state of        a process.        D    Uninterruptible sleep (usually IO)        R    Running or runnable (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.        For BSD formats and when the stat keyword is used, additional        characters may be displayed:        <    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 OBSOLETE SORT KEYS        These keys are used by the BSD O option (when it is used for sorting).        The GNU --sort option doesn't use these keys, but the specifiers        described below in the STANDARD FORMAT SPECIFIERS section. Note that        the values used in sorting are the internal values ps uses and not the        "cooked" values used in some of the output format fields (e.g. sorting        on tty will sort into device number, not according to the terminal name        displayed). Pipe ps output into the sort(1) command if you want to sort        the cooked values.        KEY   LONG         DESCRIPTION        c     cmd          simple name of executable        C     pcpu         cpu utilization        f     flags        flags as in long format F field        g     pgrp         process group ID        G     tpgid        controlling tty process group ID        j     cutime       cumulative user time        J     cstime       cumulative system time        k     utime        user time        m     min_flt      number of minor page faults        M     maj_flt      number of major page faults        n     cmin_flt     cumulative minor page faults        N     cmaj_flt     cumulative major page faults        o     session      session ID        p     pid          process ID        P     ppid         parent process ID        r     rss          resident set size        R     resident     resident pages        s     size         memory size in kilobytes        S     share        amount of shared pages        t     tty          the device number of the controlling tty        T     start_time   time process was started        U     uid          user ID number        u     user         user name        v     vsize        total VM size in kB        y     priority     kernel scheduling priority AIX FORMAT DESCRIPTORS        This ps supports AIX format descriptors, which work somewhat like the        formatting codes of printf(1) and printf(3). For example, the normal        default output can be produced with this:  ps -eo "%p %y %x %c".        The NORMAL codes are described in the next section.        CODE   NORMAL   HEADER        %C     pcpu     %CPU        %G     group    GROUP        %P     ppid     PPID        %U     user     USER        %a     args     COMMAND        %c     comm     COMMAND        %g     rgroup   RGROUP        %n     nice     NI        %p     pid      PID        %r     pgid     PGID        %t     etime    ELAPSED        %u     ruser    RUSER        %x     time     TIME        %y     tty      TTY        %z     vsz      VSZ STANDARD FORMAT SPECIFIERS        Here are the different keywords that may be used to control the output        format (e.g. with option -o) or to sort the selected processes with the        GNU-style --sort option.        For example:  ps -eo pid,user,args --sort user        This version of ps tries to recognize most of the keywords used in        other implementations of ps.        The following user-defined format specifiers may contain spaces: args,        cmd, comm, command, fname, ucmd, ucomm, lstart, bsdstart, start.        Some keywords may not be available for sorting.        CODE      HEADER DESCRIPTION        %cpu      %CPU   cpu utilization of the process in "##.#" format.                         Currently, it is the CPU time used divided by the time the                         process has been running (cputime/realtime ratio),                         expressed as a percentage. It will not add up to 100%                         unless you are lucky. (alias pcpu).        %mem      %MEM   ratio of the process's resident set size  to the physical                         memory on the machine, expressed as a percentage.                         (alias pmem).        args      COMMANDcommand with all its arguments as a string. Modifications                         to the arguments may be shown. The output in this column                         may contain spaces. A process marked is partly                         dead, waiting to be fully destroyed by its parent.                         Sometimes the process args will be unavailable; when this                         happens, ps will instead print the executable name in                         brackets. (alias cmd, command). See also the comm format                         keyword, the -f option, and the c option.                         When specified last, this column will extend to the edge                         of the display. If ps can not determine display width, as                         when output is redirected (piped) into a file or another                         command, the output width is undefined. (it may be 80,                         unlimited, determined by the TERM variable, and so on) The                         COLUMNS environment variable or --cols option may be used                         to exactly determine the width in this case. The w or -w                         option may be also be used to adjust width.        blocked   BLOCKEDmask of the blocked signals, see signal(7). According to                         the width of the field, a 32-bit or 64-bit mask in                         hexadecimal format is displayed.                         (alias sig_block, sigmask).        bsdstart  START  time the command started. If the process was started less                         than 24 hours ago, the output format is " HH:MM", else it                         is "mmm dd" (where mmm is the three letters of the month).                         See also lstart, start, start_time, and stime.        bsdtime   TIME   accumulated cpu time, user + system. The display format is                         usually "MMM:SS", but can be shifted to the right if the                         process used more than 999 minutes of cpu time.        c         C      processor utilization. Currently, this is the integer                         value of the percent usage over the lifetime of the                         process. (see %cpu).        caught    CAUGHT mask of the caught signals, see signal(7). According to                         the width of the field, a 32 or 64 bits mask in                         hexadecimal format is displayed.                         (alias sig_catch, sigcatch).        class     CLS    scheduling class of the process. (alias policy, cls).                         Field's possible values are:                         -   not reported                         TS  SCHED_OTHER                         FF  SCHED_FIFO                         RR  SCHED_RR                         B   SCHED_BATCH                         ISO SCHED_ISO                         IDL SCHED_IDLE                         ?   unknown value        cls       CLS    scheduling class of the process. (alias policy, class).                         Field's possible values are:                         -   not reported                         TS  SCHED_OTHER                         FF  SCHED_FIFO                         RR  SCHED_RR                         B   SCHED_BATCH                         ISO SCHED_ISO                         IDL SCHED_IDLE                         ?   unknown value        cmd       CMD    see args. (alias args, command).        comm      COMMANDcommand name (only the executable name). Modifications to                         the command name will not be shown. A process marked                         is partly dead, waiting to be fully destroyed by                         its parent. The output in this column may contain spaces.                         (alias ucmd, ucomm). See also the args format keyword, the                         -f option, and the c option.                         When specified last, this column will extend to the edge                         of the display. If ps can not determine display width, as                         when output is redirected (piped) into a file or another                         command, the output width is undefined. (it may be 80,                         unlimited, determined by the TERM variable, and so on) The                         COLUMNS environment variable or --cols option may be used                         to exactly determine the width in this case. The w or -w                         option may be also be used to adjust width.        command   COMMANDsee args. (alias args, cmd).        cp        CP     per-mill (tenths of a percent) CPU usage. (see %cpu).        cputime   TIME   cumulative CPU time, "[dd-]hh:mm:ss" format. (alias time).        egid      EGID   effective group ID number of the process as a decimal                         integer. (alias gid).        egroup    EGROUP effective group ID of the process. This will be the                         textual group ID, if it can be obtained and the field                         width permits, or a decimal representation otherwise.                         (alias group).        eip       EIP    instruction pointer.        esp       ESP    stack pointer.        etime     ELAPSEDelapsed time since the process was started, in the                         form [[dd-]hh:]mm:ss.        euid      EUID   effective user ID. (alias uid).        euser     EUSER  effective user name. This will be the textual user ID,                         if it can be obtained and the field width permits,                         or a decimal representation otherwise. The n option can be                         used to force the decimal representation.                         (alias uname, user).        f         F      flags associated with the process, see the PROCESS FLAGS                         section. (alias flag, flags).        fgid      FGID   filesystem access group ID. (alias fsgid).        fgroup    FGROUP filesystem access group ID. This will be the textual                         user ID, if it can be obtained and the field width                         permits, or a decimal representation otherwise.                         (alias fsgroup).        flag      F      see f. (alias f, flags).        flags     F      see f. (alias f, flag).        fname     COMMANDfirst 8 bytes of the base name of the process's executable                         file. The output in this column may contain spaces.        fuid      FUID   filesystem access user ID. (alias fsuid).        fuser     FUSER  filesystem access user ID. This will be the textual                         user ID, if it can be obtained and the field width                         permits, or a decimal representation otherwise.        gid       GID    see egid. (alias egid).        group     GROUP  see egroup. (alias egroup).        ignored   IGNOREDmask of the ignored signals, see signal(7). According to                         the width of the field, a 32-bit or 64-bit mask in                         hexadecimal format is displayed. (alias sig_ignore,                         sigignore).        label     LABEL  security label, most commonly used for SE Linux context                         data. This is for the Mandatory Access Control ("MAC")                         found on high-security systems.        lstart    STARTEDtime the command started. See also bsdstart, start,                         start_time, and stime.        lwp       LWP    lwp (light weight process, or thread) ID of the lwp being                         reported. (alias spid, tid).        ni        NI     nice value. This ranges from 19 (nicest) to -20 (not nice                         to others), see nice(1). (alias nice).        nice      NI     see ni. (alias ni).        nlwp      NLWP   number of lwps (threads) in the process. (alias thcount).        nwchan    WCHAN  address of the kernel function where the process is                         sleeping (use wchan if you want the kernel function name).                         Running tasks will display a dash ('-') in this column.        pcpu      %CPU   see %cpu. (alias %cpu).        pending   PENDINGmask of the pending signals. See signal(7). Signals                         pending on the process are distinct from signals pending                         on individual threads. Use the m option or the -m option                         to see both. According to the width of the field, a 32-bit                         or 64-bit mask in hexadecimal format is displayed.                         (alias sig).        pgid      PGID   process group ID or, equivalently, the process ID of the                         process group leader. (alias pgrp).        pgrp      PGRP   see pgid. (alias pgid).        pid       PID    process ID number of the process.        pmem      %MEM   see %mem. (alias %mem).        policy    POL    scheduling class of the process. (alias class, cls).                         Possible values are:                         -   not reported                         TS  SCHED_OTHER                         FF  SCHED_FIFO                         RR  SCHED_RR                         B   SCHED_BATCH                         ISO SCHED_ISO                         IDL SCHED_IDLE                         ?   unknown value        ppid      PPID   parent process ID.        pri       PRI    priority of the process. Higher number means lower                         priority        psr       PSR    processor that process is currently assigned to.        rgid      RGID   real group ID.        rgroup    RGROUP real group name. This will be the textual group ID, if it                         can be obtained and the field width permits, or a decimal                         representation otherwise.        rss       RSS    resident set size, the non-swapped physical memory that a                         task has used (in kiloBytes). (alias rssize, rsz).        rssize    RSS    see rss. (alias rss, rsz).        rsz       RSZ    see rss. (alias rss, rssize).        rtprio    RTPRIO realtime priority.        ruid      RUID   real user ID.        ruser     RUSER  real user ID. This will be the textual user ID, if it can                         be obtained and the field width permits, or a decimal                         representation otherwise.        s         S      minimal state display (one character). See section PROCESS                         STATE CODES for the different values. See also stat if you                         want additional information displayed. (alias state).        sched     SCH    scheduling policy of the process. The policies SCHED_OTHER                         (SCHED_NORMAL), SCHED_FIFO, SCHED_RR, SCHED_BATCH,                         SCHED_ISO, and SCHED_IDLE are respectively displayed as                         0, 1, 2, 3, 4, and 5.        sess      SESS   session ID or, equivalently, the process ID of the                         session leader. (alias session, sid).        sgi_p     P      processor that the process is currently executing on.                         Displays "*" if the process is not currently running or                         runnable.        sgid      SGID   saved group ID. (alias svgid).        sgroup    SGROUP saved group name. This will be the textual group ID, if it                         can be obtained and the field width permits, or a decimal                         representation otherwise.        sid       SID    see sess. (alias sess, session).        sig       PENDINGsee pending. (alias pending, sig_pend).        sigcatch  CAUGHT see caught. (alias caught, sig_catch).        sigignore IGNOREDsee ignored. (alias ignored, sig_ignore).        sigmask   BLOCKEDsee blocked. (alias blocked, sig_block).        size      SZ     approximate amount of swap space that would be required if                         the process were to dirty all writable pages and then be                         swapped out. This number is very rough!        spid      SPID   see lwp. (alias lwp, tid).        stackp    STACKP address of the bottom (start) of stack for the process.        start     STARTEDtime the command started. If the process was started less                         than 24 hours ago, the output format is "HH:MM:SS", else                         it is "  mmm dd" (where mmm is a three-letter month name).                         See also lstart, bsdstart, start_time, and stime.        start_timeSTART  starting time or date of the process. Only the year will                         be displayed if the process was not started the same year                         ps was invoked, or "mmmdd" if it was not started the same                         day, or "HH:MM" otherwise. See also bsdstart, start,                         lstart, and stime.        stat      STAT   multi-character process state. See section PROCESS STATE                         CODES for the different values meaning. See also s and                         state if you just want the first character displayed.        state     S      see s. (alias s).        suid      SUID   saved user ID. (alias svuid).        suser     SUSER  saved user name. This will be the textual user ID, if it                         can be obtained and the field width permits, or a decimal                         representation otherwise. (alias svuser).        svgid     SVGID  see sgid. (alias sgid).        svuid     SVUID  see suid. (alias suid).        sz        SZ     size in physical pages of the core image of the process.                         This includes text, data, and stack space. Device mappings                         are currently excluded; this is subject to change. See vsz                         and rss.        thcount   THCNT  see nlwp. (alias nlwp). number of kernel threads owned by                         the process.        tid       TID    see lwp. (alias lwp).        time      TIME   cumulative CPU time, "[dd-]hh:mm:ss" format.                         (alias cputime).        tname     TTY    controlling tty (terminal). (alias tt, tty).        tpgid     TPGID  ID of the foreground process group on the tty (terminal)                         that the process is connected to, or -1 if the process is                         not connected to a tty.        tt        TT     controlling tty (terminal). (alias tname, tty).        tty       TT     controlling tty (terminal). (alias tname, tt).        ucmd      CMD    see comm. (alias comm, ucomm).        ucomm     COMMANDsee comm. (alias comm, ucmd).        uid       UID    see euid. (alias euid).        uname     USER   see euser. (alias euser, user).        user      USER   see euser. (alias euser, uname).        vsize     VSZ    see vsz. (alias vsz).        vsz       VSZ    virtual memory size of the process in KiB                         (1024-byte units). Device mappings are currently excluded;                         this is subject to change. (alias vsize).        wchan     WCHAN  name of the kernel function in which the process is                         sleeping, a "-" if the process is running, or a "*" if the                         process is multi-threaded and ps is not displaying                         threads. ENVIRONMENT VARIABLES        The following environment variables could affect ps:        COLUMNS           Override default display width.        LINES           Override default display height.        PS_PERSONALITY           Set to one of posix, old, linux, bsd, sun, digital...           (see section PERSONALITY below).        CMD_ENV           Set to one of posix, old, linux, bsd, sun, digital...           (see section PERSONALITY below).        I_WANT_A_BROKEN_PS           Force obsolete command line interpretation.        LC_TIME           Date format.        PS_COLORS           Not currently supported.        PS_FORMAT           Default output format override. You may set this to a format string           of the type used for the -o option. The DefSysV and DefBSD values           are particularly useful.        PS_SYSMAP           Default namelist (System.map) location.        PS_SYSTEM_MAP           Default namelist (System.map) location.        POSIXLY_CORRECT           Don't find excuses to ignore bad "features".        POSIX2           When set to "on", acts as POSIXLY_CORRECT.        UNIX95           Don't find excuses to ignore bad "features".        _XPG           Cancel CMD_ENV=irix non-standard behavior.        In general, it is a bad idea to set these variables. The one exception        is CMD_ENV or PS_PERSONALITY, which could be set to Linux for normal        systems. Without that setting, ps follows the useless and bad parts of        the Unix98 standard. PERSONALITY        390        like the S/390 OpenEdition ps        aix        like AIX ps        bsd        like FreeBSD ps (totally non-standard)        compaq     like Digital Unix ps        debian     like the old Debian ps        digital    like Tru64 (was Digital Unix, was OSF/1) ps        gnu        like the old Debian ps        hp         like HP-UX ps        hpux       like HP-UX ps        irix       like Irix ps        linux      ***** RECOMMENDED *****        old        like the original Linux ps (totally non-standard)        os390      like OS/390 Open Edition ps        posix      standard        s390       like OS/390 Open Edition ps        sco        like SCO ps        sgi        like Irix ps        solaris2   like Solaris 2+ (SunOS 5) ps        sunos4     like SunOS 4 (Solaris 1) ps (totally non-standard)        svr4       standard        sysv       standard        tru64      like Tru64 (was Digital Unix, was OSF/1) ps        unix       standard        unix95     standard        unix98     standard SEE ALSO        top(1), pgrep(1), pstree(1), proc(5). STANDARDS        This ps conforms to:        1   Version 2 of the Single Unix Specification        2   The Open Group Technical Standard Base Specifications, Issue 6        3   IEEE Std 1003.1, 2004 Edition        4   X/Open System Interfaces Extension [UP XSI]        5   ISO/IEC 9945:2003 AUTHOR        ps was originally written by Branko Lankester .        Michael K. Johnson re-wrote it significantly to        use the proc filesystem, changing a few things in the process. Michael        Shields added the pid-list feature. Charles        Blake added multi-level sorting, the dirent-style        library, the device name-to-number mmaped database, the approximate        binary search directly on System.map, and many code and documentation        cleanups. David Mossberger-Tang wrote the generic BFD support for        psupdate. Albert Cahalan rewrote ps for full        Unix98 and BSD support, along with some ugly hacks for obsolete and        foreign syntax.        Please send bug reports to .        No subscription is required or suggested. Linux                            July 28, 2004                           PS(1)