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NAME

       top - display Linux processes

SYNOPSIS

       top -hv|-bcEHiOSs1 -d secs -n max -u|U user -p pid -o fld -w [cols]

       The traditional switches `-' and whitespace are optional.

DESCRIPTION

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

       The program provides a limited interactive interface for process manipulation as well as a
       much more extensive interface for 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|-bcEHiOSs1 -d secs -n max -u|U user -p pid -o fld -w [cols]

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

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

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

       -c  :Command-line/Program-name toggle
            Starts top with the last remembered `c' state reversed.  Thus, if top was  displaying
            command  lines,  now that field will show program names, and 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  :Extend-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 combined us and ni percentage; b) is the sy percentage; c) is the  total;
       and  d)  is one of two visual graphs of those representations.  See topic 4b. SUMMARY AREA
       Commands and the `t' command for additional information on that special 4-way toggle.

   2c. MEMORY Usage
       This portion consists of two lines which may express values  in  kibibytes  (KiB)  through
       exbibytes (EiB) depending on the scaling 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
         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-Task-Limits
              Removes restrictions on which tasks are 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 and Locate processing.

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

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

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

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

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

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

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

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

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

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

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

          q  :Quit

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

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

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

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

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

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

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

                  field  default    field  default    field  default
                  GID       5       GROUP     8       WCHAN    10
                  RUID      5       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 either
              the `1' or `2' command  toggle  is  pressed.   This  interactive  command  is  only
              available if a system has the requisite NUMA support.

       Note:  If  the  entire summary area has been toggled Off for any window, you would be left
       with just the message line.  In that way, you will have maximized available task rows  but
       (temporarily) sacrificed the program name in full-screen mode or the `current' 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-(reinitialize)-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) and 'L' (locate) 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.   They  will  also  have  retained  any  customizations  you  had
              previously applied, except for the `i' (idle tasks), `n' (max tasks),  `u/U'  (user
              filter),  `o/O'  (other  filter),  `v'  (hide children), `L' (locate) and scrolling
              interactive commands.

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

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

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

              Assuming the window name is visible (you have not toggled `l'  Off),  whenever  the
              `current'  window name loses its 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,graph modes
             "      # 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)