Linux下PS命令详解

要对系统中进程进行监测控制，查看状态，内存，CPU的使用情况，使用命令：/bin/ps

（1）         ps ：是显示瞬间进程的状态，并不动态连续；

（2）         top：如果想对进程运行时间监控，应该用 top 命令；

（3）         kill 用于杀死进程或者给进程发送信号；

（4）        查看文章最后的man手册，可以查看ps的每项输出的含义，to find: STANDARD FORMAT SPECIFIERS

===================================ps 的参数说明=============================

l 长格式输出；

u 按用户名和启动时间的顺序来显示进程；

j 用任务格式来显示进程；

f 用树形格式来显示进程；

a 显示所有用户的所有进程（包括其它用户）；

x 显示无控制终端的进程；

r 显示运行中的进程；

ww 避免详细参数被截断；

-A 列出所有的进程
-w 显示加宽可以显示较多的资讯
-au 显示较详细的资讯
-aux 显示所有包含其他使用者的进程

-e 显示所有进程,环境变量
-f 全格式
-h 不显示标题
-l 长格式
-w 宽输出
a   显示终端上地所有进程,包括其他用户地进程
r   只显示正在运行地进程
x   显示没有控制终端地进程

我们常用的选项是组合是 aux 或 lax，还有参数 f 的应用。
pids 只列出进程标识符,之间运用逗号分隔.该进程列表必须在命令行参数地最后一个选项后面紧接着给出,中间不能插入空格.比如：ps -f1,4,5 显示的是进程ID为1,4,5的进程

下介绍长命令行选项,这些选项都运用“--”开头：
--sort X[+|-] key [,[+|-] key [,…]] 从SORT KEYS段中选一个多字母键.“+”字符是可选地,因为默认地方向就是按数字升序或者词典顺序，“-”字符是逆序排序（即降序）.

比如： ps -jax -sort=uid,-ppid,+pid.
--help 显示帮助信息.
--version 显示该命令地版本信息.

在前面地选项说明中提到了排序键,接下来对排序键作进一步说明.需要注意地是排序中运用地值是ps运用地内部值,并非仅用于某些输出格式地伪值.排序键列表见下表.

============排序键列表==========================
c cmd   可执行地简单名称 
C cmdline   完整命令行 
f flags   长模式标志 
g pgrp   进程地组ID 
G tpgid   控制tty进程组ID 
j cutime   累计用户时间 
J cstime   累计系统时间 
k utime   用户时间 
K stime   系统时间 
m min_flt   次要页错误地数量 
M maj_flt   重点页错误地数量 
n cmin_flt 累计次要页错误 
N cmaj_flt 累计重点页错误 
o session   对话ID 
p pid   进程ID 
P ppid   父进程ID 
r rss   驻留大小 
R resident 驻留页 
s size   内存大小(千字节) 
S share   共享页地数量 
t tty   tty次要设备号 
T start_time 进程启动地时间 
U uid   UID
u user   用户名
v vsize   总地虚拟内存数量(字节) 
y priority 内核调度优先级
========================================ps aux 或 lax 输出的解释=========================

2、ps aux 或 lax 输出的解释

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

USER: 进程所有者
PID: 进程ID

%CPU: 占用的 CPU 使用率
%MEM: 占用的内存使用率
VSZ: 占用的虚拟内存大小
RSS: 占用的内存大小

TTY: 终端的次要装置号码 (minor device number of tty)

STAT: 进程状态:

START: 启动进程的时间； 
TIME: 进程消耗CPU的时间；
COMMAND:命令的名称和参数；

=========================================进程STAT状态==================================

D 无法中断的休眠状态（通常 IO 的进程）； 
R 正在运行，在可中断队列中； 
S 处于休眠状态，静止状态； 
T 停止或被追踪，暂停执行； 
W 进入内存交换（从内核2.6开始无效）； 
X 死掉的进程； 
Z 僵尸进程不存在但暂时无法消除；

W: 没有足够的记忆体分页可分配
WCHAN 正在等待的进程资源；

<: 高优先级进程
N: 低优先序进程
L: 有记忆体分页分配并锁在记忆体内 (即时系统或捱A I/O)，即,有些页被锁进内存

s 进程的领导者（在它之下有子进程）； 
l 多进程的（使用 CLONE_THREAD, 类似 NPTL pthreads）； 
+ 位于后台的进程组；

========================================kill 终止进程================================

kill 终止进程

有十几种控制进程的方法，下面是一些常用的方法:

kill -STOP [pid] 
发送SIGSTOP (17,19,23)停止一个进程，而并不消灭这个进程。

kill -CONT [pid] 
发送SIGCONT (19,18,25)重新开始一个停止的进程。

kill -KILL [pid] 
发送SIGKILL (9)强迫进程立即停止，并且不实施清理操作。

kill -9 -1 
终止你拥有的全部进程。

SIGKILL 和 SIGSTOP 信号不能被捕捉、封锁或者忽略，但是，其它的信号可以。所以这是你的终极武器。

==================================================范例==============================

$ ps
PID TTY TIME COMMAND
5800 ttyp0 00:00:00 bash
5835 ttyp0 00:00:00 ps
可以看到,显示地项目共分为四项,依次为PID(进程ID)、TTY(终端名称)、TIME(进程执行时 间)、COMMAND(该进程地命令行输入).

可以运用u选项来查看进程所有者及其他少许详细信息,如下所示：
$ 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进程前面有条横线,意味着该进程便是用户地登录shell,所以对于一个登录用户来说带短横线地进程只有一个.还可以看 到%CPU、%MEM两个选项,前者指该进程占用地CPU时间

和总时间地百分比;后者指该进程占用地内存和总内存地百分比.
在这种情况下看到了所有控制终端地进程;当然对于其他那些没有控制终端地进程 还是没有观察到,所以这时就需要运用x选项.运用x选项可以观察到所有地进程情况.

1)ps a 显示现行终端机下的所有程序，包括其他用户的程序。
2)ps -A 显示所有程序。
3)ps c 列出程序时，显示每个程序真正的指令名称，而不包含路径，参数或常驻服务的标示。
4)ps -e 此参数的效果和指定"A"参数相同。
5)ps e 列出程序时，显示每个程序所使用的环境变量。
6)ps f 用ASCII字符显示树状结构，表达程序间的相互关系。
7)ps -H 显示树状结构，表示程序间的相互关系。
8)ps -N 显示所有的程序，除了执行ps指令终端机下的程序之外。
9)ps s 采用程序信号的格式显示程序状况。
10)ps S 列出程序时，包括已中断的子程序资料。
11)ps -t<终端机编号> 　指定终端机编号，并列出属于该终端机的程序的状况。
12)ps u 　以用户为主的格式来显示程序状况。
13)ps x 　显示所有程序，不以终端机来区分。

　最常用的方法是ps -aux,然后再用管道符号导向到grep去查找特定的进程,然后再对特定的进程进行操作。

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

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 IDT  all processes on this terminal     -s processes in the sessions givena  all w/ tty, including other users  -t by ttyg  OBSOLETE -- DO NOT USE             -u by effective user ID (supports names)r  only running processes             U  processes for specified usersx  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 hierarchyluther@gliethttp:~$ man psEXAMPLESTo see every process on the system using standard syntax:   ps -e   ps -ef   ps -eF   ps -elyTo see every process on the system using BSD syntax:   ps ax   ps axuTo print a process tree:   ps -ejH   ps axjfTo get info about threads:   ps -eLf   ps axmsTo get security info:   ps -eo euser,ruser,suser,fuser,f,comm,label   ps axZ   ps -eMTo see every process running as root (real & effective ID) in userformat:   ps -U root -u root uTo 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,wchanPrint 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 LISTThese options accept a single argument in the form of a blank-separatedor 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 CONTROLThese options are used to choose the information displayed by ps. Theoutput 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 formatl               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 formatu               display user-oriented formatv               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.mapn               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 widthTHREAD 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 processesOTHER 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 <defunct> 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 privilegesPROCESS 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 groupOBSOLETE 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 priorityAIX 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      VSZSTANDARD 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 <defunct> 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                        <defunct> 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     standardSEE 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 9945:2003AUTHOR       ps was originally written by Branko Lankester <[e-mail]>.       Michael K. Johnson <[e-mail]> re-wrote it significantly to       use the proc filesystem, changing a few things in the process. Michael       Shields <[e-mail]> added the pid-list feature. Charles       Blake <[e-mail]> 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 <[e-mail]> rewrote ps for full       Unix98 and BSD support, along with some ugly hacks for obsolete and       foreign syntax.       Please send bug reports to <[e-mail]>.       No subscription is required or suggested.Linux                            July 28, 2004                           PS(1)