linux top命令详解

时间:2022-08-27 14:31:56


  • top简述

TOP是一个动态显示过程,即可以通过用户按键来不断刷新当前状态,,top命令提供了实时的对系统处理器的状态监视。

Tasks: 259 total,   2 running, 257 sleeping,   0 stopped,   0 zombie
%Cpu(s):  10.0/4.6    15[|||||||                                              ]
KiB Mem :  5971944 total,  2069108 free,  1897640 used,  2005196 buff/cache
KiB Swap:  3998716 total,  3998716 free,        0 used.  3270516 avail Mem 

  PID USER      PR  NI    VIRT    RES    SHR S  %CPU %MEM     TIME+ COMMAND     
 2383 joel      20   0 2311856 286256 168372 S  18.6  4.8  10:48.61 chromium-b+ 
 1916 joel      20   0 1520768 130752  73584 R  11.0  2.2   3:32.51 compiz      
  908 root      20   0  359740  46208  33532 S  10.3  0.8   3:37.90 Xorg        
 2542 joel      20   0 1346212 323796  99516 S  10.0  5.4   4:51.57 chromium-b+ 
 2039 joel       9 -11  507632  11780   8812 S   3.7  0.2   0:45.57 pulseaudio  
 2796 joel      20   0 1215292 157504  87592 S   3.7  2.6   0:53.10 chromium-b+
  • top第一行命令介绍

    top - 10:15:20-->当前时间 up 3:35-->系统运行时间
    1 user-->当前登陆用户数 load average: 0.81, 0.87, 0.69-->系统负载,即任务队列的平均长度。 三个数值分别为 1分钟、5分钟、15分钟前到现在的平均值

  • top第二行命令介绍(进程信息)

    Tasks: 259 total--> 进程总数 2 running-->正在运行的进程数 257 sleeping-->睡眠的进程数 0 stopped-->停止的进程数 0 zombie--> 僵尸进程数

  • top第三行命令介绍(CPU信息)

    %Cpu(s): 9.6 us-->用户空间占用CPU百分比 4.5 sy-->内核空间占用CPU百分比 0.0 ni-->用户进程空间内改变过优先级的进程占用CPU百分比 85.7 id-->空闲CPU百分比 0.3 wa-->等待输入输出的CPU时间百分比 0.0 hi--> 0.0 si--> 0.0 st-->

  • top第四、五行命令介绍(内存信息)

    KiB Mem : 5971944 total-->物理内存总量 2114336 free-->空闲内存总量 1833032 used-->使用的物理内存总量 2024576 buff/cache-->用作内核缓存的内存量
    KiB Swap: 3998716 total-->交换区总量, 3998716 free-->空闲交换区总量, 0 used-->使用的交换区总量. 3327816 avail Mem-->

  • 进程信息

    PID-->进程ID
    USER-->用户
    PR-->优先级
    NI-->nice值。负值表示高优先级,正值表示低优先级
    VIRT-->进程使用的虚拟内存总量,单位kb。VIRT=SWAP+RES
    RES-->进程使用的、未被换出的物理内存大小,单位kb。RES=CODE+DATA
    SHR-->共享内存大小,单位kb
    S-->进程状态。 D=不可中断的睡眠状态R=运行 S=睡眠T=跟踪/停止Z=僵尸进程
    %CPU-->上次更新到现在的CPU时间占用百分比
    %MEM-->进程使用的物理内存百分比
    TIME+-->进程使用的CPU时间总计,单位1/100秒
    COMMAND-->命令名/命令行

  • man top 详解

TOP(1)                                                         User Commands                                                         TOP(1)

NAME
       top - display Linux processes

SYNOPSIS
       top -hv|-bcHiOSs -d secs -n max -u|U user -p pid -o fld -w [cols]

       The traditional switches `-' and whitespace are optional.

DESCRIPTION
       The  top program provides a dynamic real-time view of a running system.  It can display system summary information as well as a list
       of processes or threads currently being managed by the Linux kernel.  The types of system summary information shown and  the  types,
       order and size of information displayed for processes are all user configurable and that configuration can be made persistent across
       restarts.

       The program provides a limited interactive interface for process manipulation as well as a much more extensive  interface  for  per‐
       sonal configuration  -- encompassing every aspect of its operation. And while top is referred to throughout this document, you are
       free to name the program anything you wish.  That new name, possibly an alias, will then be reflected on top's display and used when
       reading and writing a configuration file.

OVERVIEW
   Documentation
       The remaining Table of Contents

           1. COMMAND-LINE Options
           2. SUMMARY Display
              a. UPTIME and LOAD Averages
              b. TASK and CPU States
              c. MEMORY Usage
           3. FIELDS / Columns Display
              a. DESCRIPTIONS of Fields
              b. MANAGING Fields
           4. INTERACTIVE Commands
              a. GLOBAL Commands
              b. SUMMARY AREA Commands
              c. TASK AREA Commands
                 1. Appearance
                 2. Content
                 3. Size
                 4. Sorting
              d. COLOR Mapping
           5. ALTERNATE-DISPLAY Provisions
              a. WINDOWS Overview
              b. COMMANDS for Windows
              c. SCROLLING a Window
              d. SEARCHING in a Window
              e. FILTERING in a Window
           6. FILES
              a. SYSTEM Configuration File
              b. PERSONAL Configuration File
              c. ADDING INSPECT Entries
           7. STUPID TRICKS Sampler
              a. Kernel Magic
              b. Bouncing Windows
              c. The Big Bird Window
              d. The Ol' Switcheroo
           8. BUGS, 9. HISTORY Former top, 10. AUTHOR, 11. SEE Also

   Operation
       When  operating top, the two most important keys are the help (h or ?)  key and quit ('q') key.  Alternatively, you could simply use
       the traditional interrupt key (^C) when you're done.

       When started for the first time, you'll be presented with these traditional elements on the main top screen:  1)  Summary  Area;  2)
       Fields/Columns  Header;  3)  Task Area.  Each of these will be explored in the sections that follow.  There is also an Input/Message
       line between the Summary Area and Columns Header which needs no further explanation.

       The main top screen is generally quite adaptive to changes in terminal dimensions under X-Windows.  Other top screens  may  be  less
       so,  especially  those  with  static text.  It ultimately depends, however, on your particular window manager and terminal emulator.
       There may be occasions when their view of terminal size and current contents differs from top's view, which is always based on oper‐
       ating system calls.

       Following  any  re-size operation, if a top screen is corrupted, appears incomplete or disordered, simply typing something innocuous
       like a punctuation character or cursor motion key will usually restore it.  In extreme cases, the  following  sequence  almost  cer‐
       tainly will:
              key/cmd  objective
              ^Z       suspend top
              fg       resume top
              <Left>   force a screen redraw (if necessary)

       But  if  the display is still corrupted, there is one more step you could try.  Insert this command after top has been suspended but
       before resuming it.
              key/cmd  objective
              reset    restore your terminal settings

       Note: the width of top's display will be limited to 512 positions.  Displaying all fields  requires  approximately  250  characters.
       Remaining  screen  width  is usually allocated to any variable width columns currently visible.  The variable width columns, such as
       COMMAND, are noted in topic 3a. DESCRIPTIONS of Fields.  Actual output width may also be influenced by the -w switch, which is  dis‐
       cussed in topic 1. COMMAND-LINE Options.

       Lastly,  some  of  top's screens or functions require the use of cursor motion keys like the standard arrow keys plus the Home, End,
       PgUp and PgDn keys.  If your terminal or emulator does not provide those keys, the following combinations are accepted  as  alterna‐
       tives:
              key      equivalent-key-combinations
              Up       alt + \      or  alt + k
              Down     alt + /      or  alt + j
              Left     alt + <      or  alt + h
              Right    alt + >      or  alt + l (lower case L)
              PgUp     alt + Up     or  alt + ctrl + k
              PgDn     alt + Down   or  alt + ctrl + j
              Home     alt + Left   or  alt + ctrl + h
              End      alt + Right  or  alt + ctrl + l

       The  Up  and Down arrow keys have special significance when prompted for line input terminated with the <Enter> key.  Those keys, or
       their aliases, can be used to retrieve previous input lines which can then be edited and re-input.  And there  are  four  additional
       keys available with line oriented input.
              key      special-significance
              Up       recall older strings for re-editing
              Down     recall newer strings or erase entire line
              Insert   toggle between insert and overtype modes
              Delete   character removed at cursor, moving others left
              Home     jump to beginning of input line
              End      jump to end of input line

   Startup Defaults
       The  following  startup  defaults  assume no configuration file, thus no user customizations.  Even so, items shown with an asterisk
       (`*') could be overridden through the command-line.  All are explained in detail in the sections that follow.

           Global-defaults
              A - Alt display      Off (full-screen)
            * d - Delay time       1.5 seconds
            * H - Threads mode     Off (summarize as tasks)
              I - Irix mode        On  (no, `solaris' smp)
            * p - PID monitoring   Off (show all processes)
            * s - Secure mode      Off (unsecured)
              B - Bold enable      On  (yes, bold globally)
           Summary-Area-defaults
              l - Load Avg/Uptime  On  (thus program name)
              t - Task/Cpu states  On  (1+1 lines, see `1')
              m - Mem/Swap usage   On  (2 lines worth)
              1 - Single Cpu       Off (thus multiple cpus)
           Task-Area-defaults
              b - Bold hilite      Off (use `reverse')
            * c - Command line     Off (name, not cmdline)
            * i - Idle tasks       On  (show all tasks)
              J - Num align right  On  (not left justify)
              j - Str align right  Off (not right justify)
              R - Reverse sort     On  (pids high-to-low)
            * S - Cumulative time  Off (no, dead children)
            * u - User filter      Off (show euid only)
            * U - User filter      Off (show any uid)
              V - Forest view      On  (show as branches)
              x - Column hilite    Off (no, sort field)
              y - Row hilite       On  (yes, running tasks)
              z - color/mono       On  (show colors)

1. COMMAND-LINE Options
       The command-line syntax for top consists of:

         -hv|-bcHiOSs -d secs -n max -u|U user -p pid -o fld -w [cols]

       The typically mandatory switch ('-') and even whitespace are completely optional.

       -h | -v  :Help/Version
            Show library version and the usage prompt, then quit.

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

       -c  :Command-line/Program-name toggle
            Starts  top  with  the last remembered `c' state reversed.  Thus, if top was displaying command lines, now that field will show
            program names, and visa versa.  See the `c' interactive command for additional information.

       -d  :Delay-time interval as:  -d ss.t (secs.tenths)
            Specifies the delay between screen updates, and overrides the corresponding value in one's personal configuration file  or  the
            startup default.  Later this can be changed with the `d' or `s' interactive commands.

            Fractional  seconds  are  honored, but a negative number is not allowed.  In all cases, however, such changes are prohibited if
            top is running in Secure mode, except for root (unless the `s' command-line option was used).  For  additional  information  on
            Secure mode see topic 6a. SYSTEM Configuration File.

       -H  :Threads-mode operation
            Instructs  top  to  display individual threads.  Without this command-line option a summation of all threads in each process is
            shown.  Later this can be changed with the `H' interactive command.

       -i  :Idle-process toggle
            Starts top with the last remembered `i' state reversed.  When this toggle is Off, tasks that have not used any  CPU  since  the
            last update will not be displayed.  For additional information regarding this toggle see topic 4c. TASK AREA Commands, SIZE.

       -n  :Number-of-iterations limit as:  -n number
            Specifies the maximum number of iterations, or frames, top should produce before ending.

       -o  :Override-sort-field as:  -o fieldname
            Specifies the name of the field on which tasks will be sorted, independent of what is reflected in the configuration file.  You
            can prepend a `+' or `-' to the field name to also override the sort direction.  A leading `+' will force sorting high to  low,
            whereas a `-' will ensure a low to high ordering.

            This option exists primarily to support automated/scripted batch mode operation.

       -O  :Output-field-names
            This  option acts as a form of help for the above -o option.  It will cause top to print each of the available field names on a
            separate line, then quit.  Such names are subject to nls translation.

       -p  :Monitor-PIDs mode as:  -pN1 -pN2 ...  or  -pN1,N2,N3 ...
            Monitor only processes with specified process IDs.  This option can be given up to 20 times, or you can provide a comma  delim‐
            ited list with up to 20 pids.  Co-mingling both approaches is permitted.

            A pid value of zero will be treated as the process id of the top program itself once it is running.

            This  is  a command-line option only and should you wish to return to normal operation, it is not necessary to quit and restart
            top  -- just issue any of these interactive commands: `=', `u' or `U'.

            The `p', `u' and `U' command-line options are mutually exclusive.

       -s  :Secure-mode operation
            Starts top with secure mode forced, even for root.  This mode is far better controlled through the  system  configuration  file
            (see topic 6. FILES).

       -S  :Cumulative-time toggle
            Starts  top  with the last remembered `S' state reversed.  When Cumulative time mode is On, each process is listed with the cpu
            time that it and its dead children have used.  See the `S' interactive command for additional information regarding this mode.

       -u | -U  :User-filter-mode as:  -u | -U number or name
            Display only processes with a user id or user name matching that given.  The `-u' option matches on  effective user whereas the
            `-U' option matches on any user (real, effective, saved, or filesystem).

            Prepending  an  exclamation  point ('!') to the user id or name instructs top to display only processes with users not matching
            the one provided.

            The `p', `u' and `U' command-line options are mutually exclusive.

       -w  :Output-width-override as:  -w [ number ]
            In Batch mode, when used without an argument top will format output using the COLUMNS= and  LINES=  environment  variables,  if
            set.   Otherwise, width will be fixed at the maximum 512 columns.  With an argument, output width can be decreased or increased
            (up to 512) but the number of rows is considered unlimited.

            In normal display mode, when used without an argument top will attempt to format output using the COLUMNS= and LINES=  environ‐
            ment  variables, if set.  With an argument, output width can only be decreased, not increased.  Whether using environment vari‐
            ables or an argument with -w, when not in Batch mode actual terminal dimensions can never be exceeded.

            Note: Without the use of this command-line option, output width is always based on  the  terminal  at  which  top  was  invoked
            whether or not in Batch mode.

2. SUMMARY Display
       Each  of the following three areas are individually controlled through one or more interactive commands.  See topic 4b. SUMMARY AREA
       Commands for additional information regarding these provisions.

   2a. UPTIME and LOAD Averages
       This portion consists of a single line containing:
           program or window name, depending on display mode
           current time and length of time since last boot
           total number of users
           system load avg over the last 1, 5 and 15 minutes

   2b. TASK and CPU States
       This portion consists of a minimum of two lines.  In an SMP environment, additional lines can reflect individual CPU state  percent‐
       ages.

       Line 1 shows total tasks or threads, depending on the state of the Threads-mode toggle.  That total is further classified as:
           running; sleeping; stopped; zombie

       Line 2 shows CPU state percentages based on the interval since the last refresh.

       As  a  default,  percentages for these individual categories are displayed.  Where two labels are shown below, those for more recent
       kernel versions are shown first.
           us, user    : time running un-niced user processes
           sy, system  : time running kernel processes
           ni, nice    : time running niced user processes
           id, idle    : time spent in the kernel idle handler
           wa, IO-wait : time waiting for I/O completion
           hi : time spent servicing hardware interrupts
           si : time spent servicing software interrupts
           st : time stolen from this vm by the hypervisor

       In the alternate cpu states display modes, beyond the first tasks/threads line, an abbreviated summary is shown consisting of  these
       elements:
                      a    b     c    d
           %Cpu(s):  75.0/25.0  100[ ...

       Where:  a)  is  the  combined  us and ni percentage; b) is the sy percentage; c) is the total; and d) is one of two visual graphs of
       those representations.  See topic 4b. SUMMARY AREA Commands and the `t' command for additional information  on  that  special  4-way
       toggle.

   2c. MEMORY Usage
       This portion consists of two lines which may express values in kibibytes (KiB) through exbibytes (EiB) depending on the scaling fac‐
       tor enforced with the `E' interactive command.

       As a default, Line 1 reflects physical memory, classified as:
           total, free, used and buff/cache

       Line 2 reflects mostly virtual memory, classified as:
           total, free, used and avail (which is physical memory)

       The avail number on line 2 is an estimation of physical memory available for starting new applications,  without  swapping.   Unlike
       the  free  field, it attempts to account for readily reclaimable page cache and memory slabs.  It is available on kernels 3.14, emu‐
       lated on kernels 2.6.27+, otherwise the same as free.

       In the alternate memory display modes, two abbreviated summary lines are shown consisting of these elements:
                      a    b          c
           GiB Mem : 18.7/15.738   [ ...
           GiB Swap:  0.0/7.999    [ ...

       Where: a) is the percentage used; b) is the total available; and c) is one of two visual graphs of those representations.

       In the case of physical memory, the percentage represents the total minus the estimated avail noted above.  The `Mem'  graph  itself
       is  divided between used and any remaining memory not otherwise accounted for by avail.  See topic 4b. SUMMARY AREA Commands and the
       `m' command for additional information on that special 4-way toggle.

       This table may help in interpreting the scaled values displayed:
           KiB = kibibyte = 1024 bytes
           MiB = mebibyte = 1024 KiB = 1,048,576 bytes
           GiB = gibibyte = 1024 MiB = 1,073,741,824 bytes
           TiB = tebibyte = 1024 GiB = 1,099,511,627,776 bytes
           PiB = pebibyte = 1024 TiB = 1,125,899,906,842,624 bytes
           EiB = exbibyte = 1024 PiB = 1,152,921,504,606,846,976 bytes

3. FIELDS / Columns
   3a. DESCRIPTIONS of Fields
       Listed below are top's available process fields (columns).  They are shown in strict ascii alphabetical order.   You  may  customize
       their position and whether or not they are displayable with the `f' or `F' (Fields Management) interactive commands.

       Any  field  is  selectable  as  the  sort field, and you control whether they are sorted high-to-low or low-to-high.  For additional
       information on sort provisions see topic 4c. TASK AREA Commands, SORTING.

       The fields related to physical memory or virtual memory reference `(KiB)' which is the unsuffixed display mode.   Such  fields  may,
       however,  be  scaled  from  KiB  through PiB.  That scaling is influenced via the `e' interactive command or established for startup
       through a build option.

        1. %CPU  -- CPU Usage
           The task's share of the elapsed CPU time since the last screen update, expressed as a percentage of total CPU time.

           In a true SMP environment, if a process is multi-threaded and top is not operating in Threads mode, amounts  greater  than  100%
           may be reported.  You toggle Threads mode with the `H' interactive command.

           Also  for  multi-processor  environments, if Irix mode is Off, top will operate in Solaris mode where a task's cpu usage will be
           divided by the total number of CPUs.  You toggle Irix/Solaris modes with the `I' interactive command.

        2. %MEM  -- Memory Usage (RES)
           A task's currently used share of available physical memory.

        3. CGROUPS  -- Control Groups
           The names of the control group(s) to which a process belongs, or `-' if not applicable for that process.

           Control Groups provide for allocating resources (cpu, memory, network bandwidth, etc.) among installation-defined groups of pro‐
           cesses.  They enable fine-grained control over allocating, denying, prioritizing, managing and monitoring those resources.

           Many different hierarchies of cgroups can exist simultaneously on a system and each hierarchy is attached to one or more subsys‐
           tems.  A subsystem represents a single resource.

           Note: The CGROUPS field, unlike most columns, is not fixed-width.  When displayed, it plus any other variable width columns will
           be  allocated  all  remaining  screen width (up to the maximum 512 characters).  Even so, such variable width fields could still
           suffer truncation.  See topic 5c. SCROLLING a Window for additional information on accessing any truncated data.

        4. CODE  -- Code Size (KiB)
           The amount of physical memory devoted to executable code, also known as the Text Resident Set size or TRS.

        5. COMMAND  -- Command Name or Command Line
           Display the command line used to start a task or the name of the associated program.  You toggle between command line  and  name
           with `c', which is both a command-line option and an interactive command.

           When  you've chosen to display command lines, processes without a command line (like kernel threads) will be shown with only the
           program name in brackets, as in this example:
               [kthreadd]

           This field may also be impacted by the forest view display mode.  See the `V' interactive  command  for  additional  information
           regarding that mode.

           Note: The COMMAND field, unlike most columns, is not fixed-width.  When displayed, it plus any other variable width columns will
           be allocated all remaining screen width (up to the maximum 512 characters).  Even so, such variable  width  fields  could  still
           suffer truncation.  This is especially true for this field when command lines are being displayed (the `c' interactive command.)
           See topic 5c. SCROLLING a Window for additional information on accessing any truncated data.

        6. DATA  -- Data + Stack Size (KiB)
           The amount of physical memory devoted to other than executable code, also known as the Data Resident Set size or DRS.

        7. ENVIRON  -- Environment variables
           Display all of the environment variables, if any, as seen by the respective processes.  These variables  will  be  displayed  in
           their raw native order, not the sorted order you are accustomed to seeing with an unqualified `set'.

           Note: The ENVIRON field, unlike most columns, is not fixed-width.  When displayed, it plus any other variable width columns will
           be allocated all remaining screen width (up to the maximum 512 characters).  Even so, such variable  width  fields  could  still
           suffer  truncation.   This  is  especially  true for this field.  See topic 5c. SCROLLING a Window for additional information on
           accessing any truncated data.

        8. Flags  -- Task Flags
           This column represents the task's current scheduling flags which are expressed in  hexadecimal  notation  and  with  zeros  sup‐
           pressed.  These flags are officially documented in <linux/sched.h>.

        9. GID  -- Group Id
           The effective group ID.

       10. GROUP  -- Group Name
           The effective group name.

       11. NI  -- Nice Value
           The  nice  value  of the task.  A negative nice value means higher priority, whereas a positive nice value means lower priority.
           Zero in this field simply means priority will not be adjusted in determining a task's dispatch-ability.

       12. P  -- Last used CPU (SMP)
           A number representing the last used processor.  In a true SMP environment this will likely change frequently  since  the  kernel
           intentionally  uses  weak  affinity.  Also, the very act of running top may break this weak affinity and cause more processes to
           change CPUs more often (because of the extra demand for cpu time).

       13. PGRP  -- Process Group Id
           Every process is member of a unique process group which is used for distribution  of  signals  and  by  terminals  to  arbitrate
           requests  for  their input and output.  When a process is created (forked), it becomes a member of the process group of its par‐
           ent.  By convention, this value equals the process ID (see PID) of the first member of a process group, called the process group
           leader.

       14. PID  -- Process Id
           The  task's unique process ID, which periodically wraps, though never restarting at zero.  In kernel terms, it is a dispatchable
           entity defined by a task_struct.

           This value may also be used as: a process group ID (see PGRP); a session ID for the session leader (see SID); a thread group  ID
           for the thread group leader (see TGID); and a TTY process group ID for the process group leader (see TPGID).

       15. PPID  -- Parent Process Id
           The process ID (pid) of a task's parent.

       16. PR  -- Priority
           The  scheduling  priority  of  the task.  If you see `rt' in this field, it means the task is running under real time scheduling
           priority.

           Under linux, real time priority is somewhat misleading since traditionally the operating itself was not preemptible.  And  while
           the 2.6 kernel can be made mostly preemptible, it is not always so.

       17. RES  -- Resident Memory Size (KiB)
           The non-swapped physical memory a task is using.

       18. RUID  -- Real User Id
           The real user ID.

       19. RUSER  -- Real User Name
           The real user name.

       20. S  -- Process Status
           The status of the task which can be one of:
               D = uninterruptible sleep
               R = running
               S = sleeping
               T = stopped by job control signal
               t = stopped by debugger during trace
               Z = zombie

           Tasks  shown  as  running should be more properly thought of as ready to run  -- their task_struct is simply represented on the
           Linux run-queue.  Even without a true SMP machine, you may see numerous tasks in this state depending on  top's  delay  interval
           and nice value.

       21. SHR  -- Shared Memory Size (KiB)
           The  amount  of shared memory available to a task, not all of which is typically resident.  It simply reflects memory that could
           be potentially shared with other processes.

       22. SID  -- Session Id
           A session is a collection of process groups (see PGRP), usually established by the login shell.  A newly  forked  process  joins
           the  session  of  its  creator.   By  convention, this value equals the process ID (see PID) of the first member of the session,
           called the session leader, which is usually the login shell.

       23. SUID  -- Saved User Id
           The saved user ID.

       24. SUPGIDS  -- Supplementary Group IDs
           The IDs of any supplementary group(s) established at login or inherited from a task's parent.  They are  displayed  in  a  comma
           delimited list.

           Note: The SUPGIDS field, unlike most columns, is not fixed-width.  When displayed, it plus any other variable width columns will
           be allocated all remaining screen width (up to the maximum 512 characters).  Even so, such variable  width  fields  could  still
           suffer truncation.  See topic 5c. SCROLLING a Window for additional information on accessing any truncated data.

       25. SUPGRPS  -- Supplementary Group Names
           The  names  of any supplementary group(s) established at login or inherited from a task's parent.  They are displayed in a comma
           delimited list.

           Note: The SUPGRPS field, unlike most columns, is not fixed-width.  When displayed, it plus any other variable width columns will
           be  allocated  all  remaining  screen width (up to the maximum 512 characters).  Even so, such variable width fields could still
           suffer truncation.  See topic 5c. SCROLLING a Window for additional information on accessing any truncated data.

       26. SUSER  -- Saved User Name
           The saved user name.

       27. SWAP  -- Swapped Size (KiB)
           The non-resident portion of a task's address space.

       28. TGID  -- Thread Group Id
           The ID of the thread group to which a task belongs.  It is the PID of the thread group leader.  In kernel terms,  it  represents
           those tasks that share an mm_struct.

       29. TIME  -- CPU Time
           Total CPU time the task has used since it started.  When Cumulative mode is On, each process is listed with the cpu time that it
           and its dead children have used.  You toggle Cumulative mode with `S', which is both a command-line option  and  an  interactive
           command.  See the `S' interactive command for additional information regarding this mode.

       30. TIME+  -- CPU Time, hundredths
           The same as TIME, but reflecting more granularity through hundredths of a second.

       31. TPGID  -- Tty Process Group Id
           The  process  group  ID  of the foreground process for the connected tty, or -1 if a process is not connected to a terminal.  By
           convention, this value equals the process ID (see PID) of the process group leader (see PGRP).

       32. TTY  -- Controlling Tty
           The name of the controlling terminal.  This is usually the device (serial port, pty, etc.) from which the process  was  started,
           and  which  it  uses  for input or output.  However, a task need not be associated with a terminal, in which case you'll see `?'
           displayed.

       33. UID  -- User Id
           The effective user ID of the task's owner.

       34. USED  -- Memory in Use (KiB)
           This field represents the non-swapped physical memory a task has used (RES) plus the non-resident portion of its  address  space
           (SWAP).

       35. USER  -- User Name
           The effective user name of the task's owner.

       36. VIRT  -- Virtual Memory Size (KiB)
           The  total amount of virtual memory used by the task.  It includes all code, data and shared libraries plus pages that have been
           swapped out and pages that have been mapped but not used.

       37. WCHAN  -- Sleeping in Function
           Depending on the availability of the kernel link map (System.map), this field will show the name or the address  of  the  kernel
           function in which the task is currently sleeping.  Running tasks will display a dash ('-') in this column.

           By  displaying this field, top's own working set could be increased by over 700Kb, depending on the kernel version.  Should that
           occur, your only means of reducing that overhead will be to stop and restart top.

       38. nDRT  -- Dirty Pages Count
           The number of pages that have been modified since they were last written to auxiliary storage.  Dirty pages must be  written  to
           auxiliary storage before the corresponding physical memory location can be used for some other virtual page.

       39. nMaj  -- Major Page Fault Count
           The  number  of  major  page  faults that have occurred for a task.  A page fault occurs when a process attempts to read from or
           write to a virtual page that is not currently present in its address space.  A major page fault is when auxiliary storage access
           is involved in making that page available.

       40. nMin  -- Minor Page Fault count
           The  number  of  minor  page  faults that have occurred for a task.  A page fault occurs when a process attempts to read from or
           write to a virtual page that is not currently present in its address space.  A minor page fault does not involve auxiliary stor‐
           age access in making that page available.

       41. nTH  -- Number of Threads
           The number of threads associated with a process.

       42. nsIPC  -- IPC namespace
           The  Inode  of  the  namespace used to isolate interprocess communication (IPC) resources such as System V IPC objects and POSIX
           message queues.

       43. nsMNT  -- MNT namespace
           The Inode of the namespace used to isolate filesystem mount points thus offering different views of the filesystem hierarchy.

       44. nsNET  -- NET namespace
           The Inode of the namespace used to isolate resources such as network devices, IP addresses, IP routing, port numbers, etc.

       45. nsPID  -- PID namespace
           The Inode of the namespace used to isolate process ID numbers meaning they need not remain unique.  Thus,  each  such  namespace
           could have its own `init' (PID #1) to manage various initialization tasks and reap orphaned child processes.

       46. nsUSER  -- USER namespace
           The Inode of the namespace used to isolate the user and group ID numbers.  Thus, a process could have a normal unprivileged user
           ID outside a user namespace while having a user ID of 0, with full root privileges, inside that namespace.

       47. nsUTS  -- UTS namespace
           The Inode of the namespace used to isolate hostname and NIS domain name.  UTS simply means "UNIX Time-sharing System".

       48. vMj  -- Major Page Fault Count Delta
           The number of major page faults that have occurred since the last update (see nMaj).

       49. vMn  -- Minor Page Fault Count Delta
           The number of minor page faults that have occurred since the last update (see nMin).

   3b. MANAGING Fields
       After pressing the interactive command `f' or `F' (Fields Management) you will be presented with a screen showing: 1) the  `current'
       window  name;  2)  the  designated sort field; 3) all fields in their current order along with descriptions.  Entries marked with an
       asterisk are the currently displayed fields, screen width permitting.

           ·  As the on screen instructions indicate, you navigate among the fields with the Up and Down arrow keys.  The PgUp, PgDn,  Home
              and End keys can also be used to quickly reach the first or last available field.

           ·  The  Right  arrow key selects a field for repositioning and the Left arrow key or the <Enter> key commits that field's place‐
              ment.

           ·  The `d' key or the <Space> bar toggles a field's display status, and thus the presence or absence of the asterisk.

           ·  The `s' key designates a field as the sort field.  See topic 4c. TASK  AREA  Commands,  SORTING  for  additional  information
              regarding your selection of a sort field.

           ·  The `a' and `w' keys can be used to cycle through all available windows and the `q' or <Esc> keys exit Fields Management.

       The  Fields  Management  screen  can  also  be  used to change the `current' window/field group in either full-screen mode or alter‐
       nate-display mode.  Whatever was targeted when `q' or <Esc> was pressed will be made current as you return to the top display.   See
       topic 5. ALTERNATE-DISPLAY Provisions and the `g' interactive command for insight into `current' windows and field groups.

       Note:  Any  window that has been scrolled horizontally will be reset if any field changes are made via the Fields Management screen.
       Any vertical scrolled position, however, will not be affected.  See topic 5c. SCROLLING a Window for additional information  regard‐
       ing vertical and horizontal scrolling.

4. INTERACTIVE Commands
       Listed  below  is  a brief index of commands within categories.  Some commands appear more than once  -- their meaning or scope may
       vary depending on the context in which they are issued.

         4a. Global-Commands
               <Ent/Sp> ?, =, 0,
               A, B, d, E, e, g, h, H, I, k, q, r, s, W, X, Y, Z
         4b. Summary-Area-Commands
               C, l, t, m, 1, 2, 3
         4c. Task-Area-Commands
               Appearance:  b, J, j, x, y, z
               Content:     c, f, F, o, O, S, u, U, V
               Size:        #, i, n
               Sorting:     <, >, f, F, R
         4d. Color-Mapping
               <Ret>, a, B, b, H, M, q, S, T, w, z, 0 - 7
         5b. Commands-for-Windows
               -, _, =, +, A, a, g, G, w
         5c. Scrolling-a-Window
               C, Up, Dn, Left, Right, PgUp, PgDn, Home, End
         5d. Searching-in-a-Window
               L, &

   4a. GLOBAL Commands
       The global interactive commands are always available in both full-screen mode and alternate-display mode.  However,  some  of  these
       interactive commands are not available when running in Secure mode.

       If you wish to know in advance whether or not your top has been secured, simply ask for help and view the system summary on the sec‐
       ond line.

         <Enter> or <Space>  :Refresh-Display
              These commands awaken top and following receipt of any input the entire display will be repainted.  They also force an update
              of any hotplugged cpu or physical memory changes.

              Use either of these keys if you have a large delay interval and wish to see current status,

          ? | h  :Help
              There  are  two  help  levels available.  The first will provide a reminder of all the basic interactive commands.  If top is
              secured, that screen will be abbreviated.

              Typing `h' or `?' on that help screen will take you to help for those interactive commands  applicable  to  alternate-display
              mode.

          =  :Exit-Task-Limits
              Removes  restrictions  on which tasks are shown.  This command will reverse any `i' (idle tasks) and `n' (max tasks) commands
              that might be active.  It also provides for an exit from PID monitoring, User filtering and Other filtering.   See  the  `-p'
              command-line option for a discussion of PID monitoring, the `U' or `u' interactive commands for User filtering and the `O' or
              `o' interactive commands for Other filtering.

              Additionally, any window that has been scrolled will be reset with this command.  See topic 5c. SCROLLING a Window for  addi‐
              tional information regarding vertical and horizontal scrolling.

              When operating in alternate-display mode this command has a broader meaning.

          0  :Zero-Suppress toggle
              This command determines whether zeros are shown or suppressed for many of the fields in a task window.  Fields like UID, GID,
              NI, PR or P are not affected by this toggle.

          A  :Alternate-Display-Mode toggle
              This command will switch between full-screen mode and alternate-display mode.  See topic 5. ALTERNATE-DISPLAY Provisions  and
              the `g' interactive command for insight into `current' windows and field groups.

          B  :Bold-Disable/Enable toggle
              This  command will influence use of the bold terminfo capability and alters both the summary area and task area for the `cur‐
              rent' window.  While it is intended primarily for use with dumb terminals, it can be applied anytime.

              Note: When this toggle is On and top is operating in monochrome mode, the entire display will appear as normal  text.   Thus,
              unless the `x' and/or `y' toggles are using reverse for emphasis, there will be no visual confirmation that they are even on.

       *  d | s  :Change-Delay-Time-interval
              You will be prompted to enter the delay time, in seconds, between display updates.

              Fractional seconds are honored, but a negative number is not allowed.  Entering 0 causes (nearly) continuous updates, with an
              unsatisfactory display as the system and tty driver try to keep up with top's demands.  The delay value is inversely  propor‐
              tional to system loading, so set it with care.

              If at any time you wish to know the current delay time, simply ask for help and view the system summary on the second line.

          E  :Extend-Memory-Scale in Summary Area
              With  this  command you can cycle through the available summary area memory scaling which ranges from KiB (kibibytes or 1,024
              bytes) through EiB (exbibytes or 1,152,921,504,606,846,976 bytes).

              If you see a `+' between a displayed number and the following label, it means that top was forced to truncate some portion of
              that number.  By raising the scaling factor, such truncation can be avoided.

          e  :Extend-Memory-Scale in Task Windows
              With  this  command  you can cycle through the available task window memory scaling which ranges from KiB (kibibytes or 1,024
              bytes) through PiB (pebibytes or 1,125,899,906,842,624 bytes).

              While top will try to honor the selected target range, additional scaling might still be necessary in  order  to  accommodate
              current  values.   If you wish to see a more homogeneous result in the memory columns, raising the scaling range will usually
              accomplish that goal.  Raising it too high, however, is likely to produce an all zero result which cannot be suppressed  with
              the `0' interactive command.

          g  :Choose-Another-Window/Field-Group
              You will be prompted to enter a number between 1 and 4 designating the field group which should be made the `current' window.
              You will soon grow comfortable with these 4 windows, especially after experimenting with alternate-display mode.

          H  :Threads-mode toggle
              When this toggle is On, individual threads will be displayed for all processes in all visible task windows.   Otherwise,  top
              displays a summation of all threads in each process.

          I  :Irix/Solaris-Mode toggle
              When  operating  in  Solaris  mode  (`I' toggled Off), a task's cpu usage will be divided by the total number of CPUs.  After
              issuing this command, you'll be told the new state of this toggle.

       *  k  :Kill-a-task
              You will be prompted for a PID and then the signal to send.

              Entering no PID or a negative number will be interpreted as the default shown in the prompt (the first  task  displayed).   A
              PID value of zero means the top program itself.

              The default signal, as reflected in the prompt, is SIGTERM.  However, you can send any signal, via number or name.

              If you wish to abort the kill process, do one of the following depending on your progress:
                  1) at the pid prompt, type an invalid number
                  2) at the signal prompt, type 0 (or any invalid signal)
                  3) at any prompt, type <Esc>

          q  :Quit

       *  r  :Renice-a-Task
              You will be prompted for a PID and then the value to nice it to.

              Entering  no  PID  or a negative number will be interpreted as the default shown in the prompt (the first task displayed).  A
              PID value of zero means the top program itself.

              A positive nice value will cause a process to lose priority.  Conversely, a negative nice value will cause a  process  to  be
              viewed  more  favorably  by the kernel.  As a general rule, ordinary users can only increase the nice value and are prevented
              from lowering it.

              If you wish to abort the renice process, do one of the following depending on your progress:
                  1) at the pid prompt, type an invalid number
                  2) at the nice prompt, type <Enter> with no input
                  3) at any prompt, type <Esc>

          W  :Write-the-Configuration-File
              This will save all of your options and toggles plus the current display mode and delay time.  By issuing  this  command  just
              before quitting top, you will be able restart later in exactly that same state.

          X  :Extra-Fixed-Width
              Some  fields  are fixed width and not scalable.  As such, they are subject to truncation which would be indicated by a `+' in
              the last position.

              This interactive command can be used to alter the widths of the following fields:

                  field  default    field  default    field  default
                  GID       5       GROUP     8       WCHAN    10
                  RUID      5       RUSER     8       nsIPC    10
                  SUID      5       SUSER     8       nsMNT    10
                  UID       5       USER      8       nsNET    10
                                    TTY       8       nsPID    10
                                                      nsUSER   10
                                                      nsUTS    10

              You will be prompted for the amount to be added to the default widths shown above.  Entering zero forces a  return  to  those
              defaults.

              If  you  enter  a negative number, top will automatically increase the column size as needed until there is no more truncated
              data.  You can accelerate this process by reducing the delay interval or holding down the <Space> bar.

              Note: Whether explicitly or automatically increased, the widths for these fields are never decreased by top.  To narrow  them
              you must specify a smaller number or restore the defaults.

          Y  :Inspect-Other-Output
              After  issuing  the  `Y' interactive command, you will be prompted for a target PID.  Typing a value or accepting the default
              results in a separate screen.  That screen can be used to view a variety of files or piped command output  while  the  normal
              top iterative display is paused.

              Note:  This interactive command is only fully realized when supporting entries have been manually added to the end of the top
              configuration file.  For details on creating those entries, see topic 6c. ADDING INSPECT Entries.

              Most of the keys used to navigate the Inspect feature are reflected in its header prologue.  There are,  however,  additional
              keys  available  once  you  have  selected  a particular file or command.  They are familiar to anyone who has used the pager
              `less' and are summarized here for future reference.

                  key      function
                  =        alternate status-line, file or pipeline
                  /        find, equivalent to `L' locate
                  n        find next, equivalent to `&' locate next
                  <Space>  scroll down, equivalent to <PgDn>
                  b        scroll up, equivalent to <PgUp>
                  g        first line, equivalent to <Home>
                  G        last line, equivalent to <End>

          Z  :Change-Color-Mapping
              This key will take you to a separate screen where you can change the colors for the `current' window,  or  for  all  windows.
              For details regarding this interactive command see topic 4d. COLOR Mapping.

       *  The commands shown with an asterisk (`*') are not available in Secure mode, nor will they be shown on the level-1 help screen.

   4b. SUMMARY AREA Commands
       The  summary  area  interactive  commands are always available in both full-screen mode and alternate-display mode.  They affect the
       beginning lines of your display and will determine the position of messages and prompts.

       These commands always impact just the `current' window/field group.  See topic 5. ALTERNATE-DISPLAY Provisions and the `g'  interac‐
       tive command for insight into `current' windows and field groups.

          C  :Show-scroll-coordinates toggle
              Toggle  an  informational  message  which is displayed whenever the message line is not otherwise being used.  For additional
              information see topic 5c. SCROLLING a Window.

          l  :Load-Average/Uptime toggle
              This is also the line containing the program name (possibly an alias) when operating in full-screen  mode  or  the  `current'
              window name when operating in alternate-display mode.

          t  :Task/Cpu-States toggle
              This  command  affects  from  2 to many summary area lines, depending on the state of the `1', `2' or `3' command toggles and
              whether or not top is running under true SMP.

              This portion of the summary area is also influenced by the `H' interactive command toggle, as reflected in  the  total  label
              which shows either Tasks or Threads.

              This command serves as a 4-way toggle, cycling through these modes:
                  1. detailed percentages by category (default)
                  2. abbreviated user/system and total % + bar graph
                  3. abbreviated user/system and total % + block graph
                  4. turn off task and cpu states display

              When  operating  in  either of the graphic modes, the display becomes much more meaningful when individual CPUs or NUMA nodes
              are also displayed.  See the the `1', `2' and `3' commands below for additional information.

          m  :Memory/Swap-Usage toggle
              This command affects the two summary area lines dealing with physical and virtual memory.

              This command serves as a 4-way toggle, cycling through these modes:
                  1. detailed percentages by memory type (default)
                  2. abbreviated % used/total available + bar graph
                  3. abbreviated % used/total available + block graph
                  4. turn off memory display

          1  :Single/Separate-Cpu-States toggle
              This command affects how the `t' command's Cpu States portion is shown.  Although this toggle exists primarily to serve  mas‐
              sively-parallel SMP machines, it is not restricted to solely SMP environments.

              When you see `%Cpu(s):' in the summary area, the `1' toggle is On and all cpu information is gathered in a single line.  Oth‐
              erwise, each cpu is displayed separately as: `%Cpu0, %Cpu1, ...'  up to available screen height.

          2  :NUMA-Nodes/Cpu-Summary toggle
              This command toggles between the `1' command cpu summary display (only) or a summary display plus the  cpu  usage  statistics
              for each NUMA Node.  It is only available if a system has the requisite NUMA support.

          3  :Expand-NUMA-Node
              You  will be invited to enter a number representing a NUMA Node.  Thereafter, a node summary plus the statistics for each cpu
              in that node will be shown until either the `1' or `2' command toggle is pressed.  This interactive command is only available
              if a system has the requisite NUMA support.

       Note:  If  the  entire summary area has been toggled Off for any window, you would be left with just the message line.  In that way,
       you will have maximized available task rows but (temporarily) sacrificed the program name in full-screen mode or the `current'  win‐
       dow name when in alternate-display mode.

   4c. TASK AREA Commands
       The task area interactive commands are always available in full-screen mode.

       The  task  area  interactive  commands are never available in alternate-display mode if the `current' window's task display has been
       toggled Off (see topic 5. ALTERNATE-DISPLAY Provisions).

       APPEARANCE of task window

          J  :Justify-Numeric-Columns toggle
              Alternates between right-justified (the default) and left-justified numeric data.  If the numeric data completely  fills  the
              available column, this command toggle may impact the column header only.

          j  :Justify-Character-Columns toggle
              Alternates  between  left-justified (the default) and right-justified character data.  If the character data completely fills
              the available column, this command toggle may impact the column header only.

         The following commands will also be influenced by the state of the global `B' (bold enable) toggle.

          b  :Bold/Reverse toggle
              This command will impact how the `x' and `y' toggles are displayed.  It may also impact the summary area when a bar graph has
              been selected for cpu states or memory usage via the 't' or 'm' toggles.

          x  :Column-Highlight toggle
              Changes highlighting for the current sort field.  If you forget which field is being sorted this command can serve as a quick
              visual reminder, providing the sort field is being displayed.  The sort field might not be visible because:
                  1) there is insufficient Screen Width
                  2) the `f' interactive command turned it Off

              Note: Whenever Searching and/or Other Filtering is active in a window, column highlighting is temporarily disabled.  See  the
              notes at the end of topics 5d. SEARCHING and 5e. FILTERING for an explanation why.

          y  :Row-Highlight toggle
              Changes highlighting for "running" tasks.  For additional insight into this task state, see topic 3a. DESCRIPTIONS of Fields,
              the `S' field (Process Status).

              Use of this provision provides important insight into your system's health.  The only costs will  be  a  few  additional  tty
              escape sequences.

          z  :Color/Monochrome toggle
              Switches  the  `current'  window  between your last used color scheme and the older form of black-on-white or white-on-black.
              This command will alter both the summary area and task area but does not affect the state of the `x', `y' or `b' toggles.

       CONTENT of task window

          c  :Command-Line/Program-Name toggle
              This command will be honored whether or not the COMMAND column is currently visible.  Later,  should  that  field  come  into
              view, the change you applied will be seen.

          f | F  :Fields-Management
              These keys display a separate screen where you can change which fields are displayed, their order and also designate the sort
              field.  For additional information on these interactive commands see topic 3b. MANAGING Fields.

          o | O  :Other-Filtering
              You will be prompted for the selection criteria which then determines which tasks will be  shown  in  the  `current'  window.
              Your criteria can be made case sensitive or case can be ignored.  And you determine if top should include or exclude matching
              tasks.

              See topic 5e. FILTERING in a window for details on these and additional related interactive commands.

          S  :Cumulative-Time-Mode toggle
              When Cumulative mode is On, each process is listed with the cpu time that it and its dead children have used.

              When Off, programs that fork into many separate tasks will appear less demanding.  For programs like `init' or a  shell  this
              is appropriate but for others, like compilers, perhaps not.  Experiment with two task windows sharing the same sort field but
              with different `S' states and see which representation you prefer.

              After issuing this command, you'll be informed of the new state of this toggle.  If you wish to know in  advance  whether  or
              not Cumulative mode is in effect, simply ask for help and view the window summary on the second line.

          u | U  :Show-Specific-User-Only
              You  will  be  prompted  for the uid or name of the user to display.  The -u option matches on  effective user whereas the -U
              option matches on any user (real, effective, saved, or filesystem).

              Thereafter, in that task window only matching users will be shown, or possibly no processes will  be  shown.   Prepending  an
              exclamation  point  ('!') to the user id or name instructs top to display only processes with users not matching the one pro‐
              vided.

              Different task windows can be used to filter different users.  Later, if you wish to monitor all users again in the `current'
              window, re-issue this command but just press <Enter> at the prompt.

          V  :Forest-View-Mode toggle
              In  this  mode,  processes  are reordered according to their parents and the layout of the COMMAND column resembles that of a
              tree.  In forest view mode it is still possible to toggle between program name and command line (see the `c' interactive com‐
              mand) or between processes and threads (see the `H' interactive command).

              Note:  Typing  any  key affecting the sort order will exit forest view mode in the `current' window.  See topic 4c. TASK AREA
              Commands, SORTING for information on those keys.

       SIZE of task window

          i  :Idle-Process toggle
              Displays all tasks or just active tasks.  When this toggle is Off, tasks that have not used any CPU  since  the  last  update
              will  not  be displayed.  However, due to the granularity of the %CPU and TIME+ fields, some processes may still be displayed
              that appear to have used no CPU.

              If this command is applied to the last task display when in alternate-display mode, then it  will  not  affect  the  window's
              size, as all prior task displays will have already been painted.

          n | # :Set-Maximum-Tasks
              You  will  be  prompted to enter the number of tasks to display.  The lessor of your number and available screen rows will be
              used.

              When used in alternate-display mode, this is the command that gives you precise control over the size of each currently visi‐
              ble  task display, except for the very last.  It will not affect the last window's size, as all prior task displays will have
              already been painted.

              Note: If you wish to increase the size of the last visible task display when in alternate-display mode, simply  decrease  the
              size of the task display(s) above it.

       SORTING of task window

          For  compatibility,  this  top supports most of the former top sort keys.  Since this is primarily a service to former top users,
          these commands do not appear on any help screen.
                command   sorted-field                  supported
                A         start time (non-display)      No
                M         %MEM                          Yes
                N         PID                           Yes
                P         %CPU                          Yes
                T         TIME+                         Yes

          Before using any of the following sort provisions, top suggests that you temporarily turn on column highlighting  using  the  `x'
          interactive command.  That will help ensure that the actual sort environment matches your intent.

          The following interactive commands will only be honored when the current sort field is visible.  The sort field might not be vis‐
          ible because:
                1) there is insufficient Screen Width
                2) the `f' interactive command turned it Off

             <  :Move-Sort-Field-Left
                 Moves the sort column to the left unless the current sort field is the first field being displayed.

             >  :Move-Sort-Field-Right
                 Moves the sort column to the right unless the current sort field is the last field being displayed.

          The following interactive commands will always be honored whether or not the current sort field is visible.

             f | F  :Fields-Management
                 These keys display a separate screen where you can change which field is used as the sort column, among  other  functions.
                 This  can  be  a  convenient way to simply verify the current sort field, when running top with column highlighting turned
                 Off.

             R  :Reverse/Normal-Sort-Field toggle
                 Using this interactive command you can alternate between high-to-low and low-to-high sorts.

          Note: Field sorting uses internal values, not those in column display.  Thus, the TTY and WCHAN fields will violate strict  ASCII
          collating sequence.

   4d. COLOR Mapping
       When  you  issue  the  `Z' interactive command, you will be presented with a separate screen.  That screen can be used to change the
       colors in just the `current' window or in all four windows before returning to the top display.

       The following interactive commands are available.
           4 upper case letters to select a target
           8 numbers to select a color
           normal toggles available
               B         :bold disable/enable
               b         :running tasks "bold"/reverse
               z         :color/mono
           other commands available
               a/w       :apply, then go to next/prior
               <Enter>   :apply and exit
               q         :abandon current changes and exit

       If you use `a' or `w' to cycle the targeted window, you will have applied the color scheme that was displayed  when  you  left  that
       window.   You  can,  of  course, easily return to any window and reapply different colors or turn colors Off completely with the `z'
       toggle.

       The Color Mapping screen can also be used to change the `current' window/field group in either full-screen mode or alternate-display
       mode.  Whatever was targeted when `q' or <Enter> was pressed will be made current as you return to the top display.

5. ALTERNATE-DISPLAY Provisions
   5a. WINDOWS Overview
       Field Groups/Windows:
          In  full-screen  mode there is a single window represented by the entire screen.  That single window can still be changed to dis‐
          play 1 of 4 different field groups (see the `g' interactive command, repeated below).  Each of the 4 field groups  has  a  unique
          separately configurable summary area and its own configurable task area.

          In alternate-display mode, those 4 underlying field groups can now be made visible simultaneously, or can be turned Off individu‐
          ally at your command.

          The summary area will always exist, even if it's only the message line.  At any given time only one  summary  area  can  be  dis‐
          played.   However,  depending  on your commands, there could be from zero to four separate task displays currently showing on the
          screen.

       Current Window:
          The `current' window is the window associated with the summary area and the window to which  task  related  commands  are  always
          directed.   Since  in alternate-display mode you can toggle the task display Off, some commands might be restricted for the `cur‐
          rent' window.

          A further complication arises when you have toggled the first summary area line Off.  With the loss of the window name  (the  `l'
          toggled line), you'll not easily know what window is the `current' window.

   5b. COMMANDS for Windows
          - | _  :Show/Hide-Window(s) toggles
              The `-' key turns the `current' window's task display On and Off.  When On, that task area will show a minimum of the columns
              header you've established with the `f' interactive command.  It will also reflect any other task area options/toggles  you've
              applied yielding zero or more tasks.

              The  `_'  key does the same for all task displays.  In other words, it switches between the currently visible task display(s)
              and any task display(s) you had toggled Off.  If all 4 task displays are currently visible,  this  interactive  command  will
              leave the summary area as the only display element.

       *  = | +  :Equalize-(reinitialize)-Window(s)
              The  `='  key  forces  the  `current'  window's  task display to be visible.  It also reverses any `i' (idle tasks), `n' (max
              tasks), `u/U' (user filter) and `o/O' (other filter) commands that might be active.  Also, if the window had  been  scrolled,
              it will be reset with this command.  See topic 5c. SCROLLING a Window for additional information regarding vertical and hori‐
              zontal scrolling.

              The `+' key does the same for all windows.  The four task displays will reappear,  evenly  balanced.   They  will  also  have
              retained  any  customizations  you had previously applied, except for the `i' (idle tasks), `n' (max tasks), `u/U' (user fil‐
              ter), `o/O' (other filter) and scrolling interactive commands.

       *  A  :Alternate-Display-Mode toggle
              This command will switch between full-screen mode and alternate-display mode.

              The first time you issue this command, all four task displays will be shown.  Thereafter when you switch modes, you will  see
              only the task display(s) you've chosen to make visible.

       *  a | w  :Next-Window-Forward/Backward
              This  will change the `current' window, which in turn changes the window to which commands are directed.  These keys act in a
              circular fashion so you can reach any desired window using either key.

              Assuming the window name is visible (you have not toggled `l' Off), whenever the  `current'  window  name  loses  its  empha‐
              sis/color, that's a reminder the task display is Off and many commands will be restricted.

       *  g  :Choose-Another-Window/Field-Group
              You will be prompted to enter a number between 1 and 4 designating the field group which should be made the `current' window.

              In full-screen mode, this command is necessary to alter the `current' window.  In alternate-display mode, it is simply a less
              convenient alternative to the `a' and `w' commands.

          G  :Change-Window/Field-Group-Name
              You will be prompted for a new name to be applied to the `current' window.  It does not require that the window name be visi‐
              ble (the `l' toggle to be On).

       *  The interactive commands shown with an asterisk (`*') have use beyond alternate-display mode.
              =, A, g    are always available
              a, w       act the same with color mapping
                         and fields management

   5c. SCROLLING a Window
       Typically  a  task  window is a partial view into a systems's total tasks/threads which shows only some of the available fields/col‐
       umns.  With these scrolling keys, you can move that view vertically or horizontally to reveal any desired task or column.

       Up,PgUp  :Scroll-Tasks
           Move the view up toward the first task row, until the first task is displayed at the top of the `current' window.  The Up  arrow
           key moves a single line while PgUp scrolls the entire window.

       Down,PgDn  :Scroll-Tasks
           Move  the view down toward the last task row, until the last task is the only task displayed at the top of the `current' window.
           The Down arrow key moves a single line while PgDn scrolls the entire window.

       Left,Right  :Scroll-Columns
           Move the view of displayable fields horizontally one column at a time.

           Note: As a reminder, some fields/columns are not fixed-width but allocated  all  remaining  screen  width  when  visible.   When
           scrolling right or left, that feature may produce some unexpected results initially.

           Additionally,  there are special provisions for any variable width field when positioned as the last displayed field.  Once that
           field is reached via the right arrow key, and is thus the only column shown, you can continue scrolling horizontally within such
           a field.  See the `C' interactive command below for additional information.

       Home  :Jump-to-Home-Position
           Reposition the display to the un-scrolled coordinates.

       End  :Jump-to-End-Position
           Reposition  the  display so that the rightmost column reflects the last displayable field and the bottom task row represents the
           last task.

           Note: From this position it is still possible to scroll down and right using the arrow keys.  This is true until a single column
           and a single task is left as the only display element.

       C  :Show-scroll-coordinates toggle
           Toggle  an  informational  message  which is displayed whenever the message line is not otherwise being used.  That message will
           take one of two forms depending on whether or not a variable width column has also been scrolled.

             scroll coordinates: y = n/n (tasks), x = n/n (fields)
             scroll coordinates: y = n/n (tasks), x = n/n (fields) + nn

           The coordinates shown as n/n are relative to the upper left corner of the `current' window.  The  additional  `+ nn'  represents
           the  displacement  into  a  variable  width column when it has been scrolled horizontally.  Such displacement occurs in normal 8
           character tab stop amounts via the right and left arrow keys.

           y = n/n (tasks)
               The first n represents the topmost visible task and is controlled by scrolling keys.  The second n is updated  automatically
               to reflect total tasks.

           x = n/n (fields)
               The  first n represents the leftmost displayed column and is controlled by scrolling keys.  The second n is the total number
               of displayable fields and is established with the `f' interactive command.

       The above interactive commands are always available in full-screen mode but never available in alternate-display mode if  the  `cur‐
       rent' window's task display has been toggled Off.

       Note:  When any form of filtering is active, you can expect some slight aberrations when scrolling since not all tasks will be visi‐
       ble.  This is particularly apparent when using the Up/Down arrow keys.

   5d. SEARCHING in a Window
       You can use these interactive commands to locate a task row containing a particular value.

       L  :Locate-a-string
           You will be prompted for the case-sensitive string to locate starting  from  the  current  window  coordinates.   There  are  no
           restrictions on search string content.

           Searches  are  not  limited to values from a single field or column.  All of the values displayed in a task row are allowed in a
           search string.  You may include spaces, numbers, symbols and even forest view artwork.

           Keying <Enter> with no input will effectively disable the `&' key until a new search string is entered.

       &  :Locate-next
           Assuming a search string has been established, top will attempt to locate the next occurrence.

       When a match is found, the current window is repositioned vertically so the task row containing that string is  first.   The  scroll
       coordinates  message  can  provide  confirmation  of  such  vertical  repositioning  (see  the `C' interactive command).  Horizontal
       scrolling, however, is never altered via searching.

       The availability of a matching string will be influenced by the following factors.

          a. Which fields are displayable from the total available,
             see topic 3b. MANAGING Fields.

          b. Scrolling a window vertically and/or horizontally,
             see topic 5c. SCROLLING a Window.

          c. The state of the command/command-line toggle,
             see the `c' interactive command.

          d. The stability of the chosen sort column,
             for example PID is good but %CPU bad.

       If a search fails, restoring the `current' window home (unscrolled) position, scrolling horizontally,  displaying  command-lines  or
       choosing a more stable sort field could yet produce a successful `&' search.

       The  above  interactive commands are always available in full-screen mode but never available in alternate-display mode if the `cur‐
       rent' window's task display has been toggled Off.

       Note: Whenever a Search is active in a window, top will turn column highlighting Off to prevent false matches on  internal  non-dis‐
       play  escape sequences.  Such highlighting will be restored when a window's search string is empty.  See the `x' interactive command
       for additional information on sort column highlighting.

   5e. FILTERING in a Window
       You can use this Other Filter feature to establish selection criteria which will then determine which tasks are shown in  the  `cur‐
       rent' window.

       Establishing  a  filter requires: 1) a field name; 2) an operator; and 3) a selection value, as a minimum.  This is the most complex
       of top's user input requirements so, when you make a mistake, command recall will be your friend.  Remember the Up/Down  arrow  keys
       or their aliases when prompted for input.

       Filter Basics

          1. field names are case sensitive and spelled as in the header

          2. selection values need not comprise the full displayed field

          3. a selection is either case insensitive or sensitive to case

          4. the default is inclusion, prepending `!' denotes exclusions

          5. multiple selection criteria can be applied to a task window

          6. inclusion and exclusion criteria can be used simultaneously

          7. the 1 equality and 2 relational filters can be freely mixed

          8. separate unique filters are maintained for each task window

          If a field is not turned on or is not currently in view, then your selection criteria will not affect the display.  Later, should
          a filtered field become visible, the selection criteria will then be applied.

       Keyboard Summary

         o  :Other-Filter (lower case)
             You will be prompted to establish a filter that ignores case when matching.

         O  :Other-Filter (upper case)
             You will be prompted to establish a case sensitive filter.

        ^O  :Show-Active-Filters (Ctrl key + `o')
             This can serve as a reminder of which filters are active in the `current' window.  A summary will be shown on the message line
             until you press the <Enter> key.

         =  :Reset-Filtering in current window
             This  clears  all  of  your selection criteria in the `current' window.  It also has additional impact so please see topic 4a.
             GLOBAL Commands.

         +  :Reset-Filtering in all windows
             This clears the selection criteria in all windows, assuming you are in alternate-display mode.  As with  the  `='  interactive
             command, it too has additional consequences so you might wish to see topic 5b. COMMANDS for Windows.

       Input Requirements

          When  prompted  for selection criteria, the data you provide must take one of two forms.  There are 3 required pieces of informa‐
          tion, with a 4th as optional.  These examples use spaces for clarity but your input generally would not.
                  #1 #2 #3 ( required )
                  Field-Name   ?   include-if-value
               !  Field-Name   ?   exclude-if-value
               #4 ( optional )

          Items #1, #3 and #4 should be self-explanatory. Item #2 represents both a required delimiter and the operator which must be one
          of either equality (`=') or relation (`<' or `>').

          The  `='  equality operator requires only a partial match and that can reduce your `if-value' input requirements.  The `>' or `<'
          relational operators always employ string comparisons, even with numeric fields.  They  are  designed  to  work  with  a  field's
          default  justification  and with homogeneous data.  When some field's numeric amounts have been subjected to scaling while others
          have not, that data is no longer homogeneous.

          If you establish a relational filter and you have changed the default Numeric or Character justification, that filter  is  likely
          to  fail.   When a relational filter is applied to a memory field and you have not changed the scaling, it may produce misleading
          results.  This happens, for example, because `100.0m' (MiB) would appear greater than `1.000g' (GiB) when compared as strings.

          If your filtered results appear suspect, simply altering justification or scaling may yet achieve the desired objective.  See the
          `j', `J' and `e' interactive commands for additional information.

       Potential Problems

          These  GROUP  filters could produce the exact same results or the second one might not display anything at all, just a blank task
          window.
               GROUP=root        ( only the same results when )
               GROUP=ROOT        ( invoked via lower case `o' )

          Either of these RES filters might yield inconsistent and/or misleading results, depending on the current memory  scaling  factor.
          Or both filters could produce the exact same results.
               RES>9999          ( only the same results when )
               !RES<10000        ( memory scaling is at `KiB' )

          This  nMin  filter  illustrates  a  problem  unique to scalable fields.  This particular field can display a maximum of 4 digits,
          beyond which values are automatically scaled to KiB or above.  So while amounts greater than 9999  exist,  they  will  appear  as
          2.6m, 197k, etc.
               nMin>9999         ( always a blank task window )

       Potential Solutions

          These  examples illustrate how Other Filtering can be creatively applied to achieve almost any desired result.  Single quotes are
          sometimes shown to delimit the spaces which are part of a filter or to represent a request for status (^O)  accurately.   But  if
          you used them with if-values in real life, no matches would be found.

          Assuming  field  nTH is displayed, the first filter will result in only multi-threaded processes being shown.  It also reminds us
          that a trailing space is part of every displayed field.  The second filter achieves the exact same results with less typing.
               !nTH=` 1 '                ( ' for clarity only )
               nTH>1                     ( same with less i/p )

          With Forest View mode active and the COMMAND column in view, this filter effectively collapses child processes  so  that  just  3
          levels are shown.
               !COMMAND=`       `- '     ( ' for clarity only )

          The final two filters appear as in response to the status request key (^O).  In reality, each filter would have required separate
          input.  The PR example shows the two concurrent filters necessary to display tasks with priorities of  20  or  more,  since  some
          might be negative.  Then by exploiting trailing spaces, the nMin series of filters could achieve the failed `9999' objective dis‐
          cussed above.
               `PR>20' + `!PR=-'         ( 2 for right result )
               `!nMin=0 ' + `!nMin=1 ' + `!nMin=2 ' + `!nMin=3 ' ...

       Note: Whenever Other Filtering is active in a window, top will turn column highlighting Off to prevent  false  matches  on  internal
       non-display  escape  sequences.   Such  highlighting  will be restored when a window is no longer subject to filtering.  See the `x'
       interactive command for additional information on sort column highlighting.

6. FILES
   6a. SYSTEM Configuration File
       The presence of this file will influence which version of the help screen is shown to an ordinary user.  More importantly,  it  will
       limit what ordinary users are allowed to do when top is running.  They will not be able to issue the following commands.
           k        Kill a task
           r        Renice a task
           d or s   Change delay/sleep interval

       The system configuration file is not created by top.  Rather, you create this file manually and place it in the /etc directory.  Its
       name must be `toprc' and must have no leading `.' (period).  It must have only two lines.

       Here is an example of the contents of /etc/toprc:
           s        # line 1: secure mode switch
           5.0      # line 2: delay interval in seconds

   6b. PERSONAL Configuration File
       This file is written as `$HOME/.your-name-4-top' + `rc'.  Use the `W' interactive command to create it or update it.

       Here is the general layout:
           global   # line 1: the program name/alias notation
             " # line 2: id,altscr,irixps,delay,curwin per ea # line a: winname,fieldscur window # line b: winflags,sortindx,maxtasks,graph modes "      # line c: summclr,msgsclr,headclr,taskclr
           global   # line 15: additional miscellaneous settings
             " # any remaining lines are devoted to the "      # generalized inspect provisions
             " # discussed below If the $HOME variable is not present, top will try to write the personal configuration file to the current directory, subject to permissions. 6c. ADDING INSPECT Entries To exploit the `Y' interactive command, you must add entries at the end of the top personal configuration file. Such entries simply reflect a file to be read or command/pipeline to be executed whose results will then be displayed in a separate scrollable, search‐ able window. If you don't know the location or name of your top rcfile, use the `W' interactive command to rewrite it and note those details. Inspect entries can be added with a redirected echo or by editing the configuration file. Redirecting an echo risks overwriting the rcfile should it replace (>) rather than append (>>) to that file. Conversely, when using an editor care must be taken not to cor‐ rupt existing lines, some of which will contain unprintable data or unusual characters. Those Inspect entries beginning with a `#' character are ignored, regardless of content. Otherwise they consist of the following 3 elements, each of which must be separated by a tab character (thus 2 `\t' total): .type: literal `file' or `pipe' .name: selection shown on the Inspect screen .fmts: string representing a path or command The two types of Inspect entries are not interchangeable. Those designated `file' will be accessed using fopen and must reference a single file in the `.fmts' element. Entries specifying `pipe' will employ popen, their `.fmts' element could contain many pipelined commands and, none can be interactive. If the file or pipeline represented in your `.fmts' deals with the specific PID input or accepted when prompted, then the format string must also contain the `%d' specifier, as these examples illustrate. .fmts= /proc/%d/numa_maps .fmts= lsof -P -p %d For `pipe' type entries only, you may also wish to redirect stderr to stdout for a more comprehensive result. Thus the format string becomes: .fmts= pmap -x %d 2>&1 Here are examples of both types of Inspect entries as they might appear in the rcfile. The first entry will be ignored due to the initial `#' character. For clarity, the pseudo tab depictions (^I) are surrounded by an extra space but the actual tabs would not be. # pipe ^I Sockets ^I lsof -n -P -i 2>&1 pipe ^I Open Files ^I lsof -P -p %d 2>&1 file ^I NUMA Info ^I /proc/%d/numa_maps pipe ^I Log ^I tail -n100 /var/log/syslog | sort -Mr Except for the commented entry above, these next examples show what could be echoed to achieve similar results, assuming the rcfile name was `.toprc'. However, due to the embedded tab characters, each of these lines should be preceded by `/bin/echo -e', not just a simple an `echo', to enable backslash interpretation regardless of which shell you use. "pipe\tOpen Files\tlsof -P -p %d 2>&1" >> ~/.toprc "file\tNUMA Info\t/proc/%d/numa_maps" >> ~/.toprc "pipe\tLog\ttail -n200 /var/log/syslog | sort -Mr" >> ~/.toprc Caution: If any inspect entry you create produces output with unprintable characters they will be displayed in either the ^C nota‐ tion or hexadecimal <FF> form, depending on their value. This applies to tab characters as well, which will show as `^I'. If you want a truer representation, any embedded tabs should be expanded. # next would have contained `\t' ... # file ^I <your_name> ^I /proc/%d/status # but this will eliminate embedded `\t' ... pipe ^I <your_name> ^I cat /proc/%d/status | expand - The above example takes what could have been a `file' entry but employs a `pipe' instead so as to expand the embedded tabs. Note: While `pipe' type entries have been discussed in terms of pipelines and commands, there is nothing to prevent you from includ‐ ing shell scripts as well. Perhaps even newly created scripts designed specifically for the `Y' interactive command. Lastly, as the number of your Inspect entries grows over time, the `Options:' row will be truncated when screen width is exceeded. That does not affect operation other than to make some selections invisible. However, if some choices are lost to truncation but you want to see more options, there is an easy solution hinted at below. Inspection Pause at pid ... Use: left/right then <Enter> ... Options: help 1 2 3 4 5 6 7 8 9 10 11 ... The entries in the top rcfile would have a number for the `.name' element and the `help' entry would identify a shell script you've written explaining what those numbered selections actually mean. In that way, many more choices can be made visible. 7. STUPID TRICKS Sampler Many of these tricks work best when you give top a scheduling boost. So plan on starting him with a nice value of -10, assuming you've got the authority. 7a. Kernel Magic For these stupid tricks, top needs full-screen mode. · The user interface, through prompts and help, intentionally implies that the delay interval is limited to tenths of a second. However, you're free to set any desired delay. If you want to see Linux at his scheduling best, try a delay of .09 seconds or less. For this experiment, under x-windows open an xterm and maximize it. Then do the following: . provide a scheduling boost and tiny delay via: nice -n -10 top -d.09 . keep sorted column highlighting Off so as to minimize path length . turn On reverse row highlighting for emphasis . try various sort columns (TIME/MEM work well), and normal or reverse sorts to bring the most active processes into view What you'll see is a very busy Linux doing what he's always done for you, but there was no program available to illustrate this. · Under an xterm using `white-on-black' colors, on top's Color Mapping screen set the task color to black and be sure that task highlighting is set to bold, not reverse. Then set the delay interval to around .3 seconds. After bringing the most active processes into view, what you'll see are the ghostly images of just the currently running tasks. · Delete the existing rcfile, or create a new symlink. Start this new version then type `T' (a secret key, see topic 4c. Task Area Commands, SORTING) followed by `W' and `q'. Finally, restart the program with -d0 (zero delay). Your display will be refreshed at three times the rate of the former top, a 300% speed advantage. As top climbs the TIME ladder, be as patient as you can while speculating on whether or not top will ever reach the top. 7b. Bouncing Windows For these stupid tricks, top needs alternate-display mode. · With 3 or 4 task displays visible, pick any window other than the last and turn idle processes Off using the `i' command toggle. Depending on where you applied `i', sometimes several task displays are bouncing and sometimes it's like an accordion, as top tries his best to allocate space. · Set each window's summary lines differently: one with no memory ('m'); another with no states ('t'); maybe one with nothing at all, just the message line. Then hold down `a' or `w' and watch a variation on bouncing windows -- hopping windows. · Display all 4 windows and for each, in turn, set idle processes to Off using the `i' command toggle. You've just entered the "extreme bounce" zone. 7c. The Big Bird Window This stupid trick also requires alternate-display mode. · Display all 4 windows and make sure that 1:Def is the `current' window. Then, keep increasing window size with the `n' interac‐ tive command until all the other task displays are "pushed out of the nest". When they've all been displaced, toggle between all visible/invisible windows using the `_' command toggle. Then ponder this: is top fibbing or telling honestly your imposed truth? 7d. The Ol' Switcheroo This stupid trick works best without alternate-display mode, since justification is active on a per window basis. · Start top and make COMMAND the last (rightmost) column displayed. If necessary, use the `c' command toggle to display command lines and ensure that forest view mode is active with the `V' command toggle. Then use the up/down arrow keys to position the display so that some truncated command lines are shown (`+' in last position). You may have to resize your xterm to produce truncation. Lastly, use the `j' command toggle to make the COMMAND column right justified. Now use the right arrow key to reach the COMMAND column. Continuing with the right arrow key, watch closely the direction of travel for the command lines being shown. some lines travel left, while others travel right eventually all lines will Switcheroo, and move right 8. BUGS To report bugs, follow the instructions at: http://www.debian.org/Bugs/Reporting 9. HISTORY Former top The original top was written by Roger Binns, based on Branko Lankester's <lankeste@fwi.uva.nl> ps program. Robert Nation <nation@rocket.sanders.lockheed.com> adapted it for the proc file system. Helmut Geyer <Helmut.Geyer@iwr.uni-heidelberg.de> added support for configurable fields. Plus many other individuals contributed over the years. 10. AUTHOR This entirely new and enhanced replacement was written by: Jim Warner, <james.warner@comcast.net> With invaluable help from: Craig Small, <csmall@enc.com.au> Albert Cahalan, <albert@users.sf.net> 11. SEE Also free(1), ps(1), uptime(1), atop(1), slabtop(1), vmstat(8), w(1).