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NAME

       top - display Linux processes

SYNOPSIS

       top -hv|-bcEeHiOSs1 -d secs -n max -u|U user -p pids -o field -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  personal  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

           OVERVIEW
              Operation
              Linux Memory Types
           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. PERSONAL Configuration File
              b. ADDING INSPECT Entries
              c. SYSTEM Configuration File
              d. SYSTEM Restrictions File
           7. STUPID TRICKS Sampler
              a. Kernel Magic
              b. Bouncing Windows
              c. The Big Bird Window
              d. The Ol' Switcheroo
           8. BUGS, 9. 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 operating 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 certainly 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 discussed 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 alternatives:
              key      equivalent-keys
              Left     alt + h
              Down     alt + j
              Up       alt + k
              Right    alt + l
              Home     alt + ctrl + h
              PgDn     alt + ctrl + j
              PgUp     alt + ctrl + k
              End      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

   Linux Memory Types
       For our purposes there are three types of memory, and one is  optional.   First  is  physical  memory,  a
       limited  resource where code and data must reside when executed or referenced.  Next is the optional swap
       file, where modified (dirty) memory can be saved and later retrieved if too  many  demands  are  made  on
       physical memory.  Lastly we have virtual memory, a nearly unlimited resource serving the following goals:

          1. abstraction, free from physical memory addresses/limits
          2. isolation, every process in a separate address space
          3. sharing, a single mapping can serve multiple needs
          4. flexibility, assign a virtual address to a file

       Regardless  of  which of these forms memory may take, all are managed as pages (typically 4096 bytes) but
       expressed by default in top as KiB (kibibyte).  The memory discussed under topic `2c. MEMORY Usage' deals
       with  physical  memory  and  the  swap  file for the system as a whole.  The memory reviewed in topic `3.
       FIELDS / Columns Display' embraces all three memory types, but for individual processes.

       For each such process, every memory page is restricted to a single quadrant from the table  below.   Both
       physical  memory  and  virtual  memory  can include any of the four, while the swap file only includes #1
       through #3.  The memory in quadrant #4, when modified, acts as its own dedicated swap file.

                                     Private | Shared
                                 1           |          2
            Anonymous  . stack               |
                       . malloc()            |
                       . brk()/sbrk()        | . POSIX shm*
                       . mmap(PRIVATE, ANON) | . mmap(SHARED, ANON)
                      -----------------------+----------------------
                       . mmap(PRIVATE, fd)   | . mmap(SHARED, fd)
          File-backed  . pgms/shared libs    |
                                 3           |          4

       The following may help in interpreting process level memory values  displayed  as  scalable  columns  and
       discussed under topic `3a. DESCRIPTIONS of Fields'.

          %MEM - simply RES divided by total physical memory
          CODE - the `pgms' portion of quadrant 3
          DATA - the entire quadrant 1 portion of VIRT plus all
                 explicit mmap file-backed pages of quadrant 3
          RES  - anything occupying physical memory which, beginning with
                 Linux-4.5, is the sum of the following three fields:
                 RSan - quadrant 1 pages, which include any
                        former quadrant 3 pages if modified
                 RSfd - quadrant 3 and quadrant 4 pages
                 RSsh - quadrant 2 pages
          RSlk - subset of RES which cannot be swapped out (any quadrant)
          SHR  - subset of RES (excludes 1, includes all 2 & 4, some 3)
          SWAP - potentially any quadrant except 4
          USED - simply the sum of RES and SWAP
          VIRT - everything in-use and/or reserved (all quadrants)

       Note:  Even  though program images and shared libraries are considered private to a process, they will be
       accounted for as shared (SHR) by the kernel.

1. COMMAND-LINE Options

       The command-line syntax for top consists of:

         -hv|-bcEeHiOSs1 -d secs -n max -u|U user -p pids -o field -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  vice 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  6d.  SYSTEM
            Restrictions File.

       -e  :Enforce-Task-Memory-Scaling as:  -e  k | m | g | t | p
            Instructs top to force task area memory to be scaled as:
               k - kibibytes
               m - mebibytes
               g - gibibytes
               t - tebibytes
               p - pebibytes

            Later this can be changed with the `e' command toggle.

       -E  :Enforce-Summary-Memory-Scaling as:  -E  k | m | g | t | p | e
            Instructs top to force summary area memory to be scaled as:
               k - kibibytes
               m - mebibytes
               g - gibibytes
               t - tebibytes
               p - pebibytes
               e - exbibytes

            Later this can be changed with the `E' command toggle.

       -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  (National
            Language Support) 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 delimited 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  a
            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=  environment  variables,  if  set.  With an argument, output width can only be
            decreased, not increased.  Whether using environment variables 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.

       -1  :Single/Separate-Cpu-States toggle
            Starts top with the last remembered Cpu States portion of the summary area reversed.  Either all cpu
            information  will  be displayed in a single line or each cpu will be displayed separately, depending
            on the state of the NUMA Node command toggle ('2').

            See the `1' and '2' interactive commands for additional information.

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 percentages.

       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  `user' (us + ni) percentage; b) is the `system' (sy + hi + si) 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 factor 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, emulated 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.

           Note: When running in forest view mode (`V') with children collapsed  (`v'),  this  field  will  also
           include  the  CPU  time of those unseen children.  See topic 4c. TASK AREA Commands, CONTENT for more
           information regarding the `V' and `v' toggles.

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

           See `OVERVIEW, Linux Memory Types' for additional details.

        3. CGNAME  --  Control Group Name
           The name of the control group to which a process belongs, or `-' if not applicable for that process.

           This will typically be the last entry in the full list of control groups  as  shown  under  the  next
           heading (CGROUPS).  And as is true there, this field is also variable width.

        4. 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 processes.  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 subsystems.  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.

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

           See `OVERVIEW, Linux Memory Types' for additional details.

        6. 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.

        7. DATA  --  Data + Stack Size (KiB)
           The  amount  of  private  memory reserved by a process.  It is also known as the Data Resident Set or
           DRS.  Such memory may not yet be mapped to physical memory (RES) but will always be included  in  the
           virtual memory (VIRT) amount.

           See `OVERVIEW, Linux Memory Types' for additional details.

        8. 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.

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

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

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

       12. LXC  --  Lxc Container Name
           The name of the lxc container within which a task is running.  If a process is not running  inside  a
           container, a dash (`-') will be shown.

       13. 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.

       14. NU  --  Last known NUMA node
           A  number  representing  the  NUMA  node  associated  with the last used processor (`P').  When -1 is
           displayed it means that NUMA information is not available.

           See the `'2' and `3' interactive commands for additional NUMA provisions affecting the summary area.

       15. OOMa  --  Out of Memory Adjustment Factor
           The value, ranging from -1000 to +1000, added to the current out of memory score (OOMs) which is then
           used to determine which task to kill when memory is exhausted.

       16. OOMs  --  Out of Memory Score
           The  value,  ranging  from 0 to +1000, used to select task(s) to kill when memory is exhausted.  Zero
           translates to `never kill' whereas 1000 means `always kill'.

       17. 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).

       18. 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 parent.  By convention, this value equals the process ID
           (see PID) of the first member of a process group, called the process group leader.

       19. 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).

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

       21. 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.

       22. RES  --  Resident Memory Size (KiB)
           A  subset  of the virtual address space (VIRT) representing the non-swapped physical memory a task is
           currently using.  It is also the sum of the RSan, RSfd and RSsh fields.

           It can include private anonymous pages, private pages mapped to files (including program  images  and
           shared  libraries)  plus  shared  anonymous  pages.   All  such  memory  is  backed  by the swap file
           represented separately under SWAP.

           Lastly, this field may also include shared file-backed pages which, when modified, act as a dedicated
           swap file and thus will never impact SWAP.

           See `OVERVIEW, Linux Memory Types' for additional details.

       23. RSan  --  Resident Anonymous Memory Size (KiB)
           A subset of resident memory (RES) representing private pages not mapped to a file.

       24. RSfd  --  Resident File-Backed Memory Size (KiB)
           A  subset of resident memory (RES) representing the implicitly shared pages supporting program images
           and shared libraries.  It also includes explicit file mappings, both private and shared.

       25. RSlk  --  Resident Locked Memory Size (KiB)
           A subset of resident memory (RES) which cannot be swapped out.

       26. RSsh  --  Resident Shared Memory Size (KiB)
           A subset of resident memory (RES) representing the explicitly shared anonymous shm*/mmap pages.

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

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

       29. S  --  Process Status
           The status of the task which can be one of:
               D = uninterruptible sleep
               I = idle
               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.

       30. SHR  --  Shared Memory Size (KiB)
           A subset of resident memory (RES) that may be used  by  other  processes.   It  will  include  shared
           anonymous  pages  and  shared  file-backed  pages.   It  also  includes private pages mapped to files
           representing program images and shared libraries.

           See `OVERVIEW, Linux Memory Types' for additional details.

       31. 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.

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

       33. 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.

       34. 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.

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

       36. SWAP  --  Swapped Size (KiB)
           The formerly resident portion of a task's address space written to the swap file when physical memory
           becomes over committed.

           See `OVERVIEW, Linux Memory Types' for additional details.

       37. 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.

       38. 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.

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

       40. 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).

       41. 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.

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

       43. USED  --  Memory in Use (KiB)
           This field represents the non-swapped physical memory a task is using  (RES)  plus  the  swapped  out
           portion of its address space (SWAP).

           See `OVERVIEW, Linux Memory Types' for additional details.

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

       45. 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.

           See `OVERVIEW, Linux Memory Types' for additional details.

       46. WCHAN  --  Sleeping in Function
           This field will show the name of the kernel  function  in  which  the  task  is  currently  sleeping.
           Running tasks will display a dash (`-') in this column.

       47. 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.

           This field was deprecated with linux 2.6 and is always zero.

       48. 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.

       49. 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 storage access in making that page available.

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

       51. 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.

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

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

       54. 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/systemd' (PID #1) to manage various initialization
           tasks and reap orphaned child processes.

       55. 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.

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

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

       58. 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 placement.

           •  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 alternate-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 regarding 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, 4, !
         4c. Task-Area-Commands
               Appearance:  b, J, j, x, y, z
               Content:     c, f, F, o, O, S, u, U, V, 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 second 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-Display-Limits
              Removes  restrictions  on what is shown.  This command will reverse any `i' (idle tasks), `n' (max
              tasks) and `v' (hide children) commands that might be active.  It also provides for an  exit  from
              PID monitoring, User filtering, Other filtering, Locate processing and Combine Cpus mode.

              Additionally, if the window has been scrolled it will be reset with this command.

          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  `current'  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 proportional 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  :Enforce-Summary-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  :Enforce-Task-Memory-Scale in Task Area
              With  this  command you can cycle through the available task area 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       LXC       8       nsIPC    10
                  SUID      5       RUSER     8       nsMNT    10
                  UID       5       SUSER     8       nsNET    10
                                    TTY       8       nsPID    10
                                    USER      8       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
              6b. 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' interactive 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
                  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
                  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  massively-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.  Otherwise, 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 the `1', `2' or `4' command toggle is
              pressed.  This interactive command is only available if a system has the requisite NUMA support.

          4  :Display-Cpus-Two-Abreast
              This command turns the `1' toggle Off for individual  cpu  display  but  prints  the  results  two
              abreast.   It  requires  a  terminal with a minimum width of 80 columns.  If a terminal's width is
              decreased below the minimum while top is running, top reverts to the normal `1' toggle Off state.

              To  avoid  truncation  when  displaying  detailed  cpu  statistcs,  as  opposed  to  the   graphic
              representations, a minimum width of 165 columns would be required.

          !  :Combine-Cpus-Mode
              This  command  toggle is intended for massively parallel SMP environments where, even with the `4'
              command toggle, not all processors can be displayed.   With  each  press  of  `!'  the  number  of
              additional cpu's combined is doubled thus reducing the total number of cpu lines displayed.

              For  example,  with  the  first  press of `!' one additional cpu will be combined and displayed as
              `0-1, 2-3, ...' instead of the normal `%Cpu0, %Cpu1,  %Cpu2,  %Cpu3,  ...'.   With  a  second  `!'
              command  toggle two additional cpus are combined and shown as `0-2, 3-5, ...'.  Then the third '!'
              press, combining four additional cpus, shows as `0-4, 5-9, ...', etc.

              Such progression continues until individual cpus are again displayed and impacts both the `1'  and
              `4' toggles (one or two columns).  Use the `=' command to exit Combine Cpus mode.

       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' window 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 provided.

              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 command) 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.

          v  :Hide/Show-Children toggle
              When  in  forest  view  mode,  this key serves as a toggle to collapse or expand the children of a
              parent.

              The toggle is applied against the first (topmost) process in the `current' window.  See topic  5c.
              SCROLLING a Window for additional information regarding vertical scrolling.

              If  the target process has not forked any children, this key has no effect.  It also has no effect
              when not in forest view mode.

       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  visible 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 visible 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 display 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 individually 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 displayed.  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 `current' 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/Reset-Window(s)
              The `=' key forces the `current' window's task display to be visible.  It also reverses any active
              `i' (idle tasks), `n' (max tasks), `u/U' (user filter), `o/O' (other filter), `v' (hide children),
              `L'  (locate)  and `!' (combine cpus) commands.  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 horizontal scrolling.

              The `+' key does the same for all windows.  The four task displays will reappear, evenly balanced,
              while retaining any customizations previously applied beyond  those  noted  for  the  `='  command
              toggle.

       *  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 emphasis/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 visible (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/columns.   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 `current' 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 visible.  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 `current' 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-display 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 `current' window.  Such filters can be made presistent if preserved in the rcfile
       via the 'W' interactive command.

       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  information,  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 discussed 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. PERSONAL Configuration File
       This file is created or updated via the 'W' interactive command.

       The legacy version is written as `$HOME/.your-name-4-top' + `rc' with a leading period.

       A newly created configuration file is written as procps/your-name-4-top' + `rc' without a leading period.
       The procps directory will be subordinate to either $XDG_CONFIG_HOME when set as an absolute path  or  the
       $HOME/.config directory.

       While not intended to be edited manually, 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,etc
             "      # line  c: summclr,msgsclr,headclr,taskclr
           global   # line 15: additional miscellaneous settings
             "      # any remaining lines are devoted to optional
             "      # active 'other filters' discussed in section 5e above
             "      # plus 'inspect' entries discussed in section 6b below

       If  a  valid absolute path to the rcfile cannot be established, customizations made to a running top will
       be impossible to preserve.

   6b. 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, searchable 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 corrupt 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

       If  any  inspect  entry  you create produces output with unprintable characters they will be displayed in
       either the ^C notation 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.  The following example takes what could have been a `file' entry but employs a `pipe'
       instead so as to expand the embedded tabs.

         # 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 -

       Note:  Some  programs  might  rely  on  SIGINT  to  end.  Therefore, if a `pipe' such as the following is
       established, one must use Ctrl-C to terminate it in order to review the  results.   This  is  the  single
       occasion where a `^C' will not also terminate top.

         pipe ^I Trace ^I /usr/bin/strace -p %d 2>&1

       Lastly,  while  `pipe'  type  entries  have  been  discussed in terms of pipelines and commands, there is
       nothing to prevent you from including  shell  scripts  as  well.   Perhaps  even  newly  created  scripts
       designed specifically for the `Y' interactive command.

       For  example, 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.

   6c. SYSTEM Configuration File
       This configuration file represents defaults for users who have not saved their  own  configuration  file.
       The  format  mirrors  exactly  the  personal configuration file and can also include `inspect' entries as
       explained above.

       Creating it is a simple process.

       1. Configure top appropriately for your  installation  and  preserve  that  configuration  with  the  `W'
       interactive command.

       2. Add and test any desired `inspect' entries.

       3. Copy that configuration file to the /etc/ directory as `topdefaultrc'.

   6d. SYSTEM Restrictions 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

       This configuration file is not created by top.  Rather, it is created manually and placed it in the /etc/
       directory as `toprc'.

       It should have exactly two lines, as shown in this example:
           s        # line 1: secure mode switch
           5.0      # line 2: delay interval in seconds

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' interactive 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

       Please send bug reports to ⟨procps@freelists.org⟩.

9. SEE Also

       free(1), ps(1), uptime(1), atop(1), slabtop(1), vmstat(8), w(1)