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NAME

       top - display Linux processes

SYNOPSIS

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

       The traditional switches `-' and whitespace are optional.

DESCRIPTION

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

       The program provides a limited interactive interface for process manipulation as well as a
       much more extensive interface for 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

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

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

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

       The main top screen is generally quite adaptive to changes in terminal dimensions under X-
       Windows.   Other  top  screens  may  be  less  so,  especially those with static text.  It
       ultimately depends, however, on your particular  window  manager  and  terminal  emulator.
       There  may be occasions when their view of terminal size and current contents differs from
       top's view, which is always based on 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-key-combinations
              Up       alt + \      or  alt + k
              Down     alt + /      or  alt + j
              Left     alt + <      or  alt + h
              Right    alt + >      or  alt + l (lower case L)
              PgUp     alt + Up     or  alt + ctrl + k
              PgDn     alt + Down   or  alt + ctrl + j
              Home     alt + Left   or  alt + ctrl + h
              End      alt + Right  or  alt + ctrl + l

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

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

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

1. COMMAND-LINE Options

       The command-line syntax for top consists of:

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

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

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

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

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

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

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

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

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

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

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

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

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

       -p  :Monitor-PIDs mode as:  -pN1 -pN2 ...  or  -pN1,N2,N3 ...
            Monitor only processes with specified process IDs.  This option can be given up to 20
            times,  or  you  can  provide a comma 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 the system configuration file (see topic 6. FILES).

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

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

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

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

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

            In normal display mode, when used without an argument  top  will  attempt  to  format
            output  using  the  COLUMNS=  and  LINES=  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.

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.

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

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

           Control Groups provide for allocating resources (cpu, memory, network bandwidth, etc.)
           among installation-defined groups of 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.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

           •  The Right arrow key selects a field for repositioning and the Left arrow key or the
              <Enter> key commits that field's 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
               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)  and `n' (max tasks) commands that might be active.  It also provides
              for an exit from PID monitoring, User filtering and Other filtering.  See the  `-p'
              command-line  option for a discussion of PID monitoring, the `U' or `u' interactive
              commands for User filtering and the `O'  or  `o'  interactive  commands  for  Other
              filtering.

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

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

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

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

          B  :Bold-Disable/Enable toggle
              This command will influence use of the bold terminfo capability and alters both the
              summary area and task  area  for  the  `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       RUSER     8       nsIPC    10
                  SUID      5       SUSER     8       nsMNT    10
                  UID       5       USER      8       nsNET    10
                                    TTY       8       nsPID    10
                                                      nsUSER   10
                                                      nsUTS    10

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

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

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

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

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

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

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

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

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

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

       These  commands  always  impact  just  the  `current'  window/field  group.   See topic 5.
       ALTERNATE-DISPLAY Provisions and the `g' 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 (default)
                  2. abbreviated user/system and total % + bar graph
                  3. abbreviated user/system and total % + block graph
                  4. turn off task and cpu states display

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

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

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

          1  :Single/Separate-Cpu-States toggle
              This command affects how the `t' command's Cpu States portion is  shown.   Although
              this  toggle  exists  primarily to serve 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.

       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  `i'  (idle  tasks),  `n'  (max tasks), `u/U' (user filter) and `o/O'
              (other filter) commands that might  be  active.   Also,  if  the  window  had  been
              scrolled, it will be reset with this command.  See topic 5c. SCROLLING a Window for
              additional information regarding vertical and 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) 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.

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

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

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

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

       Here is the general layout:
           global   # line  1: the program name/alias notation
             "      # line  2: id,altscr,irixps,delay,curwin
           per ea   # line  a: winname,fieldscur
           window   # line  b: winflags,sortindx,maxtasks,graph modes
             "      # line  c: summclr,msgsclr,headclr,taskclr
           global   # line 15: additional miscellaneous settings
             "      # any remaining lines are devoted to the
             "      # generalized inspect provisions
             "      # discussed below

       If  the  $HOME  variable  is not present, top will try to write the personal configuration
       file to the current directory, subject to permissions.

   6c. ADDING INSPECT Entries
       To exploit the `Y' interactive command, you must  add  entries  at  the  end  of  the  top
       personal  configuration  file.   Such  entries  simply  reflect  a  file  to  be  read  or
       command/pipeline to be executed whose  results  will  then  be  displayed  in  a  separate
       scrollable, 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

       Caution:  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.

         # next would have contained `\t' ...
         # file ^I <your_name> ^I /proc/%d/status
         # but this will eliminate embedded `\t' ...
         pipe ^I <your_name> ^I cat /proc/%d/status | expand -

       The above example takes what could have been a `file' entry but employs a  `pipe'  instead
       so as to expand the embedded tabs.

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

       Lastly,  as the number of your Inspect entries grows over time, the `Options:' row will be
       truncated when screen width is exceeded.  That does not affect  operation  other  than  to
       make some selections invisible.

       However, if some choices are lost to truncation but you want to see more options, there is
       an easy solution hinted at below.

         Inspection Pause at pid ...
         Use:  left/right then <Enter> ...
         Options:  help  1  2  3  4  5  6  7  8  9  10  11 ...

       The entries in the top rcfile would have a number for the `.name' element and  the  `help'
       entry  would  identify  a  shell  script  you've  written  explaining  what those numbered
       selections actually mean.  In that way, many more choices can be made visible.

7. STUPID TRICKS Sampler

       Many of these tricks work best when you give top a scheduling boost.  So plan on  starting
       him with a nice value of -10, assuming you've got the authority.

   7a. Kernel Magic
       For these stupid tricks, top needs full-screen mode.

       •  The  user  interface,  through  prompts  and help, intentionally implies that the delay
          interval is limited to tenths of a second.  However, you're free  to  set  any  desired
          delay.   If you want to see Linux at his scheduling best, try a delay of .09 seconds or
          less.

          For this experiment, under x-windows open an  xterm  and  maximize  it.   Then  do  the
          following:
            . provide a scheduling boost and tiny delay via:
                nice -n -10 top -d.09
            . keep sorted column highlighting Off so as to
              minimize path length
            . turn On reverse row highlighting for emphasis
            . try various sort columns (TIME/MEM work well),
              and normal or reverse sorts to bring the most
              active processes into view

          What you'll see is a very busy Linux doing what he's always done for you, but there was
          no program available to illustrate this.

       •  Under an xterm using `white-on-black' colors, on top's Color  Mapping  screen  set  the
          task  color  to  black  and be sure that task highlighting is set to bold, not reverse.
          Then set the delay interval to around .3 seconds.

          After bringing the most active processes into view, what you'll  see  are  the  ghostly
          images of just the currently running tasks.

       •  Delete  the existing rcfile, or create a new symlink.  Start this new version then type
          `T' (a secret key, see topic 4c. Task Area Commands, SORTING) followed by `W' and  `q'.
          Finally, restart the program with -d0 (zero delay).

          Your  display will be refreshed at three times the rate of the former top, a 300% speed
          advantage.  As top climbs the TIME ladder, be as patient as you can  while  speculating
          on whether or not top will ever reach the top.

   7b. Bouncing Windows
       For these stupid tricks, top needs alternate-display mode.

       •  With  3  or  4 task displays visible, pick any window other than the last and turn idle
          processes Off using the `i' command  toggle.   Depending  on  where  you  applied  `i',
          sometimes  several  task displays are bouncing and sometimes it's like an accordion, as
          top tries his best to allocate space.

       •  Set each window's summary lines differently: one with no memory ('m'); another with  no
          states ('t'); maybe one with nothing at all, just the message line.  Then hold down `a'
          or `w' and watch a variation on bouncing windows  --  hopping windows.

       •  Display all 4 windows and for each, in turn, set idle processes to Off  using  the  `i'
          command toggle.  You've just entered the "extreme bounce" zone.

   7c. The Big Bird Window
       This stupid trick also requires alternate-display mode.

       •  Display  all  4  windows  and make sure that 1:Def is the `current' window.  Then, keep
          increasing window size with the `n'  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

       To report bugs, follow the instructions at:
           http://www.debian.org/Bugs/Reporting

9. HISTORY Former top

       The  original  top  was  written   by   Roger   Binns,   based   on   Branko   Lankester's
       <lankeste@fwi.uva.nl> ps program.

       Robert Nation <nation@rocket.sanders.lockheed.com> adapted it for the proc file system.

       Helmut Geyer <Helmut.Geyer@iwr.uni-heidelberg.de> added support for configurable fields.

       Plus many other individuals contributed over the years.

10. AUTHOR

       This entirely new and enhanced replacement was written by:
           Jim Warner, <james.warner@comcast.net>

       With invaluable help from:
           Craig Small, <csmall@enc.com.au>
           Albert Cahalan, <albert@users.sf.net>

11. SEE Also

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