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TOP(1)                        User Commands                        TOP(1)



NAME
       top - display Linux processes


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


       The traditional switches '-' and whitespace are optional.


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

       The  program  provides a limited interactive interface for process
       manipulation as well as a much more extensive interface  for  per-
       sonal  configuration   --  encompassing every aspect of its opera-
       tion.  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/Mes-
       sage  line between the Summary Area and Columns Header which needs
       no further explanation.

       The main top screen is generally quite adaptive to changes in ter-
       minal  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  cur-
       rent  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 innocu-
       ous like a punctuation character or cursor motion key will usually
       restore  it.  In extreme cases, the following sequence almost cer-
       tainly will:
              key/cmd  objective
              ^Z       suspend top
              fg       resume top
                 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 cur-
       sor  motion  keys like the standard arrow keys plus the Home, End,
       PgUp and PgDn keys.  If your terminal or emulator does not provide
       those  keys,  the  following combinations are accepted as alterna-
       tives:
              key      equivalent-key-combinations
              Up       alt + \      or  alt + k
              Down     alt + /      or  alt + j
              Left     alt + <      or  alt + h
              Right    alt + >      or  alt + l (lower case L)
              PgUp     alt + Up     or  alt + ctrl + k
              PgDn     alt + Down   or  alt + ctrl + j
              Home     alt + Left   or  alt + ctrl + h
              End      alt + Right  or  alt + ctrl + l

       The Up and Down arrow keys have special significance when prompted
       for  line  input  terminated with the  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       3.0 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       On  (thus 1 line if smp)
           Task-Area-defaults
              'b' - Bold hilite      On  (not '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)
              'x' - Column hilite    Off (no, sort field)
              'y' - Row hilite       On  (yes, running tasks)
              'z' - color/mono       Off (no, 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  switches  ('-') 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'  inter-
            active 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 infor-
            mation 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 infor-
            mation  regarding  this  toggle  see topic 4c. TASK AREA Com-
            mands, 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  sort-
            ing  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  com-
            mands: '=', 'u' or 'U'.

            The 'p', 'u' and 'U' command-line options are mutually exclu-
            sive.


       -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 match-
            ing the one provided.

            The 'p', 'u' and 'U' command-line options are mutually exclu-
            sive.


       -w  :Output-width-override as:  -w [ number ]
            In 'Batch' mode, when used without an argument top will  for-
            mat  output  using  the COLUMNS= and LINES= environment vari-
            ables, 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 provi-
       sions.


   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  envi-
       ronment,  additional  lines  can reflect individual CPU state per-
       centages.

       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.  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
           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


   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.

       Line 1 reflects physical memory, classified as:
           total, used, free and buffers

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

       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 infor-
       mation on sort provisions see topic 4c. TASK AREA Commands,  SORT-
       ING.

       The  fields related to physical memory or virtual memory reference
       '(KiB)' as the default, unsuffixed display mode.  Such fields can,
       however, be scaled differently via the 'e' interactive command.


        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 sub-
           systems.  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  col-
           umns  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 Win-
           dow 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 informa-
           tion regarding that mode.

           Note:  The 'COMMAND' field, unlike most columns, is not fixed-
           width.  When displayed, it plus any other variable width  col-
           umns  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 accus-
           tomed 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 col-
           umns 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
           .


        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 ker-
           nel intentionally uses weak affinity.  Also, the very  act  of
           running  top  may break this weak affinity and cause more pro-
           cesses 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 cre-
           ated (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  dispatch-
           able 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' schedul-
           ing 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 has used.


       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 = traced or stopped
               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), usu-
           ally 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 col-
           umns 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 Win-
           dow  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 col-
           umns 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 Win-
           dow  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 repre-
           sents 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  con-
           nected 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  ('Sys-
           tem.map'), this field will show the name or the address of the
           kernel function in which the task is currently sleeping.  Run-
           ning 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 writ-
           ten 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 commu-
           nication (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 hierar-
           chy.


       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 names-
           pace could have its own 'init' (PID #1) to manage various ini-
           tialization 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 Manage-
       ment) you will be presented with a screen showing:  1)  the  'cur-
       rent'  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 per-
       mitting.


           o  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.


           o  The  Right  arrow key selects a field for repositioning and
              the Left arrow key or the  key commits that  field's
              placement.


           o  The  'd'  key  or the  bar toggles a field's display
              status, and thus the presence or absence of the asterisk.


           o  The 's' key designates a field  as  the  sort  field.   See
              topic 4c. TASK AREA Commands, SORTING for additional infor-
              mation regarding your selection of a sort field.


           o  The 'a' and 'w' keys can  be  used  to  cycle  through  all
              available  windows  and  the  'q' or  keys exit Fields
              Management.


       The Fields Management screen can also be used to change the  'cur-
       rent'  window/field  group  in  either  full-screen mode or alter-
       nate-display mode.  Whatever was targeted when 'q'  or    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
                ?, =, 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
               , 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.


          or   :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  pro-
              vide  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-dis-
              play mode.


          =  :Exit-Task-Limits
              Removes restrictions on which tasks are shown.   This  com-
              mand  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' fil-
              tering.  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 horizon-
              tal 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 sup-
              pressed 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 mono-
              chrome 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 sec-
              ond line.


          E  :Extend-Memory-Scale in Summary Area
              With  this command you can cycle through the available sum-
              mary 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 follow-
              ing  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 scal-
              ing 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  com-
              mand.


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


          H  :Threads-mode toggle
              When  this  toggle  is  On, individual threads will be dis-
              played for all processes in all visible task windows.  Oth-
              erwise,  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  fol-
              lowing depending on your progress:
                  1) at the pid prompt, type an invalid number
                  2) at the signal prompt, type 0 (or any invalid signal)


          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  prior-
              ity.   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 fol-
              lowing depending on your progress:
                  1) at the pid prompt, type an invalid number
                  2) at the nice prompt, type  with no input


          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  com-
              mand  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
                                                      nsUSR    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 reduc-
              ing the delay interval or holding down the  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 particu-
              lar  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
                    scroll down, equivalent to 
                  'b'      scroll up, equivalent to 
                  'g'      first line, equivalent to 
                  'G'      last line, equivalent to 


          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 win-
              dows.   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 addi-
              tional 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 'cur-
              rent' 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 tog-
              gles 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'.


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


          1  :Single/Separate-Cpu-States toggle
              This  command affects how the 't' command's Cpu States por-
              tion 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 sta-
              tistics for each NUMA Node.  It is only available if a sys-
              tem 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 win-
       dow,  you  would be left with just the message line.  In that way,
       you will have maximized available task rows but (temporarily) sac-
       rificed the program name in full-screen mode or the 'current' win-
       dow name when in alternate-display mode.


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

       The  task  area interactive commands are never available in alter-
       nate-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.   Further,  it  will  only  be available when at
              least one of those toggles is On.

          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 dis-
              abled.  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 inter-
              active 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' win-
              dow.  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 rep-
              resentation 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,  effec-
              tive, 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
               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 granu-
              larity 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  win-
              dow'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  dis-
              play.   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 cur-
              rently 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 vis-
         ible because:
              1) there is insufficient Screen Width
              2) the 'f' interactive command turned it Off

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

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

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

          f | F  :Fields-Management
              These keys display a separate screen where you  can  change
              which  field  is used as the sort column, among other func-
              tions.  This can be a convenient way to simply  verify  the
              current sort field, when running top with column highlight-
              ing 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
                  :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 reap-
       ply  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  was pressed  will
       be made current as you return to the top display.

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

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

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

       Current Window:
          The 'current' window is the window associated with the  summary
          area  and  the window to which task related commands are always
          directed.  Since in alternate-display mode you can  toggle  the
          task  display  Off,  some  commands might be restricted for the
          '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' interac-
              tive 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  dis-
              play(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  fil-
              ter)  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  dis-
              plays 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
              'current' 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 des-
              ignating 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/col-
       umns.  With these scrolling keys, you can move  that  view  verti-
       cally 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  unex-
           pected 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 vari-
           able 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'  repre-
           sents  the  displacement  into a variable width column when it
           has been scrolled horizontally.  Such displacement  occurs  in
           normal  8  character  tab  stop amounts via the right and left
           arrow keys.

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

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

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

       Note:  When  any  form of filtering is active, you can expect some
       slight aberrations when scrolling since not all tasks will be vis-
       ible.   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  con-
       taining 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 col-
           umn.  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  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  verti-
       cally so the task row containing that string is first.  The scroll
       coordinates message can  provide  confirmation  of  such  vertical
       repositioning  (see  the  'C'  interactive  command).   Horizontal
       scrolling, however, is never altered via searching.

       The availability of a matching string will be  influenced  by  the
       following factors.
          a. Which fields are displayable from the total available,
             see topic 3b. MANAGING Fields.
          b. Scrolling a window vertically and/or horizontally,
             see topic 5c. SCROLLING a Window.
          c. The state of the command/command-line toggle,
             see the 'c' interactive command.
          d. The stability of the chosen sort column,
             for example PID is good but %CPU bad.

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

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

       Note: Whenever a search key is typed, top will turn  column  high-
       lighting  Off  to  prevent  false  matches on internal non-display
       escape sequences.  Such highlighting will be restored when a  win-
       dow'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 the 'Other Filter' feature to establish selection cri-
       teria which will then determine which tasks are shown in the 'cur-
       rent' window.

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

       Filter Basics
          .  field names are case sensitive and spelled as in the header
          .  selection values need not comprise the full displayed field
          .  a selection is either case insensitive or sensitive to case
          .  the default is inclusion, prepending '!' denotes exclusions
          .  multiple selection criteria can be applied to a task window
          .  inclusion and exclusion criteria can be used simultaneously
          .  the 1 equality and 2 relational filters can be freely mixed
          .  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 mes-
             sage line until you press the  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 '=' interac-
             tive command, it too  has  additional  consequences  so  you
             might wish to see topic 5b. COMMANDS for Windows.

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

          Items #1, #3 and #4 should be self-explanatory.  Item #2 repre-
          sents  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  mem-
          ory  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 justi-
          fication or scaling may yet achieve the desired objective.  See
          the 'j', 'J' and 'e' interactive commands for additional infor-
          mation.

       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  dig-
          its,  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 cre-
          atively 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)  accu-
          rately.   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 fil-
          ters necessary to display tasks with priorities of 20 or  more,
          since some might be negative.  Then by exploiting trailing spa-
          ces, 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:  When  'Other  Filtering'  is active, top turns column high-
       lighting Off to prevent  false  matches  on  internal  non-display
       escape  sequences.  Such highlighting will be restored when a win-
       dow 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 run-
       ning.  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
             "      # line  c: summclr,msgsclr,headclr,taskclr
           global   # line 15: fixed-width incr
             "      # 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 sim-
       ply 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  char-
       acters,  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  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  ^I /proc/%d/status
         # but this will eliminate embedded '\t' ...
         pipe ^I  ^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  ...
         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.

       o  The  user  interface,  through  prompts and help, intentionally
          implies that the delay interval is limited to tenths of a  sec-
          ond.   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.

       o  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.

       o  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.

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

       o  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.

       o  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.

       o  Display all 4 windows and make sure that 1:Def is the 'current'
          window.  Then, keep increasing window size with the 'n'  inter-
          active  command  until  all the other task displays are "pushed
          out of the nest".

          When they've all  been  displaced,  toggle  between  all  visi-
          ble/invisible  windows using the '_' command toggle.  Then pon-
          der 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.

       o  Start  top  and  make  COMMAND the last (rightmost) column dis-
          played.  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.  Con-
          tinuing 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  ps program.

       Robert Nation  adapted it  for
       the proc file system.

       Helmut  Geyer    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, 

       With invaluable help from:
           Craig Small, 
           Albert Cahalan, 


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



procps-ng                     November 2013                        TOP(1)



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