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    Command:

    top

    
    
    
    

    SYNOPSIS

           top -hv | -abcHimMsS -d delay -n iterations -p pid [, pid ...]
    
           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  tasks
           currently  being managed by the Linux kernel.  The types of system sum-
           mary information shown and the types, order  and  size  of  information
           displayed  for  tasks  are all user configurable and that configuration
           can be made persistent across restarts.
    
           The program provides a limited interactive interface for process manip-
           ulation as well as a much more extensive interface for personal config-
           uration  --  encompassing every aspect of its operation.  And while top
           is  referred to throughout this document, you are free to name the pro-
           gram anything you wish.  That new name, possibly an alias, will then be
           reflected on top's display and used when reading and writing a configu-
           ration file.
    
    
    

    OVERVIEW

       Documentation
           The remaining Table of Contents
               1. COMMAND-LINE Options
               2. FIELDS / Columns
                  a. DESCRIPTIONS of Fields
                  b. SELECTING and ORDERING Columns
               3. INTERACTIVE Commands
                  a. GLOBAL Commands
                  b. SUMMARY Area Commands
                  c. TASK Area Commands
                  d. COLOR Mapping
               4. ALTERNATE-DISPLAY Mode
                  a. WINDOWS Overview
                  b. COMMANDS for Windows
               5. FILES
                  a. SYSTEM Configuration File
                  b. PERSONAL Configuration File
               6. STUPID TRICKS Sampler
                  a. Kernel Magic
                  b. Bouncing Windows
                  c. The Big Bird Window
               7. BUGS, 8. HISTORY Former top, 9. AUTHOR, 10. SEE ALSO
    
    
              Task_Area: Tasks running (or ready to run) will be highlighted,  and
              bold is only one way of emphasizing such processes.
    
           Content/Labels
              Summary_Area: The program name is shown, perhaps a symlink or alias.
              The Cpu(s) state label hints at  other  possibilities.   The  memory
              stats use a lower case 'k'.
    
              Columns_Header: Will show a new field and some changed labels.  More
              new fields will be found as you customize your top.
    
           Note: the width of top's display will  be  limited  to  512  positions.
           Displaying  all  fields  requires  a  minimum  of  160 characters.  The
           remaining width could be used for the 'Command' column.
    
       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.
    
               Global_defaults
                  'A' - Alt display      Off (full-screen)
                * 'd' - Delay time       3.0 seconds
                  'I' - Irix mode        On  (no, 'solaris' smp)
                * 'p' - PID monitoring   Off
                * 's' - Secure mode      Off (unsecured)
                  'B' - Bold disable     Off
               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)
                * 'H' - Threads          Off (show all threads)
                * 'i' - Idle tasks       On  (show all tasks)
                  'R' - Reverse sort     On  (pids high-to-low)
                * 'S' - Cumulative time  Off (no, dead children)
                  '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:
    
                set with the '-n' command-line option or until killed.
    
           -c : Command line/Program name toggle
                Starts top with the last remembered 'c' state reversed.  Thus,  if
                top was displaying command lines, now that field will show program
                names, and visa versa.  See the 'c' interactive command for  addi-
                tional information.
    
           -d : Delay time interval as:  -d ss.tt (seconds.tenths)
                Specifies the delay between screen updates, and overrides the cor-
                responding value in  one's  personal  configuration  file  or  the
                startup  default.   Later  this can be changed with the 'd' or 's'
                interactive commands.
    
                Fractional seconds are honored,  but  a  negative  number  is  not
                allowed.   In  all  cases, however, such changes are prohibited if
                top is running in 'Secure mode', except for root (unless  the  's'
                command-line  option  was  used).   For  additional information on
                'Secure mode' see topic 5a. SYSTEM Configuration File.
    
           -h : Help
                Show library version and the usage prompt, then quit.
    
           -H : Threads toggle
                Starts top with the last remembered 'H' state reversed.  When this
                toggle  is  On,  all individual threads will be displayed.  Other-
                wise, top displays a summation of all threads in a process.
    
           -i : Idle Processes toggle
                Starts top with the last remembered 'i' state reversed.  When this
                toggle  is  Off,  tasks that are idled or zombied will not be dis-
                played.
    
           -m : VIRT/USED toggle
                Reports USED (sum of process rss and swap total count) instead  of
                VIRT
    
           -M : Detect memory units
                Show memory units (k/M/G) and display floating point values in the
                memory summary.
    
           -n : Number of iterations limit as:  -n number
                Specifies the maximum number of iterations, or frames, top  should
                produce before ending.
                Starts top with secure mode forced, even for root.  This  mode  is
                far  better  controlled through the system configuration file (see
                topic 5. FILES).
    
           -S : Cumulative time mode toggle
                Starts top with the last  remembered  'S'  state  reversed.   When
                'Cumulative  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 : Monitor by user as:  -u somebody
                Monitor only processes with an effective UID or user name matching
                that given.
    
           -U : Monitor by user as:  -U somebody
                Monitor only processes with a  UID  or  user  name  matching  that
                given.   This matches real, effective, saved, and filesystem UIDs.
    
           -v : Version
                Show library version and the usage prompt, then quit.
    
    
    

    2. FIELDS / Columns

       2a. DESCRIPTIONS of Fields
           Listed below are top's available fields.  They  are  always  associated
           with  the  letter shown, regardless of the position you may have estab-
           lished for them with the 'o' (Order fields) interactive command.
    
           Any field is selectable as the sort field, and you control whether they
           are  sorted  high-to-low or low-to-high.  For additional information on
           sort provisions see topic 3c. TASK Area Commands.
    
           a: PID  --  Process Id
              The task's unique process ID, which periodically wraps, though never
              restarting at zero.
    
           b: PPID  --  Parent Process Pid
              The process ID of a task's parent.
    
           c: RUSER  --  Real User Name
              The real user name of the task's owner.
    
           d: UID  --  User Id
              The effective user ID of the task's owner.
              associated with a terminal, in which case you'll see '?'  displayed.
    
           h: PR  --  Priority
              The priority of the task.
    
           i: NI  --  Nice value
              The nice value of the task.  A negative nice value means higher pri-
              ority, whereas a positive nice value means lower priority.  Zero  in
              this field simply means priority will not be adjusted in determining
              a task's dispatchability.
    
           j: P  --  Last used CPU (SMP)
              A number representing the last used processor.  In a true SMP  envi-
              ronment  this  will likely change frequently since the kernel inten-
              tionally uses weak affinity.  Also, the very act of running top  may
              break  this  weak  affinity  and cause more processes to change CPUs
              more often (because of the extra demand for cpu time).
    
           k: %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 '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.
    
           l: 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 has used.  You toggle 'Cumulative mode' with 'S',
              which is a command-line option and an interactive command.  See  the
              'S'  interactive  command  for additional information regarding this
              mode.
    
           m: TIME+  --  CPU Time, hundredths
              The same as 'TIME', but reflecting  more  granularity  through  hun-
              dredths of a second.
    
           n: %MEM  --  Memory usage (RES)
              A task's currently used share of available physical memory.
    
           o: VIRT  --  Virtual Image (kb)
              The  total  amount  of virtual memory used by the task.  It includes
              all code, data and  shared  libraries  plus  pages  that  have  been
    
           r: CODE  --  Code size (kb)
              The amount of physical memory devoted to executable code, also known
              as the 'text resident set' size or TRS.
    
           s: DATA  --  Data+Stack size (kb)
              The amount of physical memory devoted to other than executable code,
              also known as the 'data resident set' size or DRS.
    
           t: SHR  --  Shared Mem size (kb)
              The amount of shared memory used by a task.  It simply reflects mem-
              ory that could be potentially shared with other processes.
    
           u: nFLT  --  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 disk access is involved in making that page
              available.
    
           v: nDRT  --  Dirty Pages count
              The  number  of  pages  that have been modified since they were last
              written to disk.  Dirty pages must be written  to  disk  before  the
              corresponding  physical  memory  location can be used for some other
              virtual page.
    
           w: 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.
    
           x: Command  --  Command line or Program name
              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  pro-
    
           y: WCHAN  --  Sleeping in Function
              Depending on the availability of the kernel link map ('System.map'),
              this field will show the name or the address of the kernel  function
              in which the task is currently sleeping.  Running tasks will display
              a dash ('-') in this column.
    
              Note: By displaying this  field,  top's  own  working  set  will  be
              increased  by over 700Kb.  Your only means of reducing that overhead
              will be to stop and restart top.
    
           z: Flags  --  Task Flags
              This column represents the task's current scheduling flags which are
              expressed  in hexadecimal notation and with zeros suppressed.  These
              flags are officially documented  in  <linux/sched.h>.   Less  formal
              documentation  can  also  be found on the 'Fields select' and 'Order
              fields' screens.
    
       2b. SELECTING and ORDERING Columns
           After pressing the interactive commands  'f'  (Fields  select)  or  ?o'
           (Order fields) you will be shown a screen containing the current fields
           string followed by names and descriptions for all fields.
    
           Here is a sample fields string from one  of  top's  four  windows/field
           groups and an explanation of the conventions used:
    
           -  Sample fields string:
                 ANOPQRSTUVXbcdefgjlmyzWHIK
    
           -  The  order  of displayed fields corresponds to the order of the let-
              ters in that string.
    
           -  If the letter is upper case the corresponding field itself will then
              be  shown  as  part  of  the task display (screen width permitting).
              This will also be indicated by a leading asterisk ('*'), as in  this
              excerpt:
                  ...
                  * K: %CPU       = CPU usage
                    l: TIME       = CPU Time
                    m: TIME+      = CPU Time, hundredths
                  * N: %MEM       = Memory usage (RES)
                  * O: VIRT       = Virtual Image (kb)
                  ...
    
           Fields select screen  --  the 'f' interactive command
              You toggle the display of a field by simply pressing the correspond-
              ing letter.
    
           Order fields screen  --  the 'o' interactive command
               st = steal (time given to other DomU instances)
    
    
    

    3. INTERACTIVE Commands

           Listed below is a brief index of commands within categories.  Some com-
           mands  appear  more  than  once   --   their  meaning or scope may vary
           depending on the context in which they are issued.
    
             3a. GLOBAL_Commands
                   <Ret/Sp> ?, =, A, B, d, G, h, I, k, q, r, s, W, Z
             3b. SUMMARY_Area_Commands
                   l, m, t, 1
             3c. TASK_Area_Commands
                   Appearance:  b, x, y, z
                   Content:     c, f, H, o, S, u
                   Size:        #, i, n
                   Sorting:     <, >, F, O, R
             3d. COLOR_Mapping
                   <Ret>, a, B, b, H, M, q, S, T, w, z, 0 - 7
             4b. COMMANDS_for_Windows
                   -, _, =, +, A, a, G, g, w
    
       3a. GLOBAL Commands
           The  global  interactive  commands  are  always   available   in   both
           full-screen  mode  and  alternate-display mode.  However, some of these
           interactive commands are not available when running in 'Secure mode'.
    
           If you wish to know in  advance  whether  or  not  your  top  has  been
           secured,  simply ask for help and view the system summary on the second
           line.
    
             <Enter> or <Space> :Refresh_Display
                  These commands do nothing, they are  simply  ignored.   However,
                  they  will  awaken  top  and  following receipt of any input the
                  entire display will be repainted.
    
                  Use either of these keys if you have a large delay interval  and
                  wish to see current status,
    
             ??? or ?h? :Help
                  There  are  two help levels available.  The first will provide a
                  reminder of all the  basic  interactive  commands.   If  top  is
                  secured, that screen will be abbreviated.
    
                  Typing  'h' or '?' on that help screen will take you to help for
                  those interactive commands applicable to alternate-display mode.
    
                  '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 capabil-
                  ity and alters both the summary area and task area for the ?cur-
                  rent'  window.  While it is intended primarily for use with dumb
                  terminals, it can be applied anytime.
    
                  Note: When this toggle is On and top is operating in  monochrome
                  mode,  the  entire  display  will  appear as normal text.  Thus,
                  unless the 'x' and/or 'y' toggles are using reverse  for  empha-
                  sis, there will be no visual confirmation that they are even on.
    
           * ?d? or ?s? :Change_Delay_Time_interval
                  You will be prompted  to  enter  the  delay  time,  in  seconds,
                  between display updates.
    
                  Fractional  seconds  are  honored,  but a negative number is not
                  allowed.  Entering 0 causes (nearly) continuous updates, with an
                  unsatisfactory  display as the system and tty driver try to keep
                  up with top's demands.  The delay  value  is  inversely  propor-
                  tional to system loading, so set it with care.
    
                  If  at  any time you wish to know the current delay time, simply
                  ask for help and view the system summary on the second line.
    
             ?G? :Choose_Another_Window/Field_Group
                  You will be prompted to enter a number between 1 and 4 designat-
                  ing  the  window/field  group which should be made the ?current'
                  window.  You will soon grow comfortable with  these  4  windows,
                  especially after experimenting with alternate-display mode.
    
             ?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  issu-
                  ing  this  command,  you'll be informed of the new state of this
                  toggle.
    
             ?u? :select a user
                  You will be prompted for  a  UID  or  username.  Only  processes
                  belonging  to  the  selected user will be displayed. This option
                  matches on the effective UID.
    
             ?U? :select a user
                  You will be prompted for  a  UID  or  username.  Only  processes
    
             ?q? :Quit
    
           * ?r? :Renice_a_Task
                  You will be prompted for a PID and then the value to nice it to.
                  Entering a positive value will cause a process to lose priority.
                  Conversely,  a  negative value will cause a process to be viewed
                  more favorably by the kernel.
    
             ?W? :Write_the_Configuration_File
                  This will save all of your options and toggles plus the  current
                  display  mode  and  delay  time.   By  issuing this command just
                  before quitting top, you will be able restart later  in  exactly
                  that same state.
    
             ?Z? :Change_Color_Mapping
                  This key will take you to a separate screen where you can change
                  the colors for the ?current' window, or for  all  windows.   For
                  details  regarding  this interactive command see topic 3d. 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.
    
       3b. 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 4. ALTERNATE-DISPLAY Mode and the 'G' interactive command for
           insight into ?current' windows and field groups.
    
             ?l? :Toggle_Load_Average/Uptime  --  On/Off
                  This is also the line containing the program name  (possibly  an
                  alias)  when operating in full-screen mode or the ?current' win-
                  dow name when operating in alternate-display mode.
    
             ?m? :Toggle_Memory/Swap_Usage  --  On/Off
                  This command affects two summary area lines.
    
             ?t? :Toggle_Task/Cpu_States  --  On/Off
                  This command affects from 2 to many summary area lines,  depend-
    
           Note:  If  the entire summary area has been toggled Off for any window,
           you would be left with just the message line.  In that  way,  you  will
           have  maximized  available  task  rows but (temporarily) sacrificed the
           program name in full-screen mode or the ?current' window name  when  in
           alternate-display mode.
    
       3c. 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 tog-
           gled Off (see topic 4. ALTERNATE-DISPLAY Mode).
    
           APPEARANCE of task window
             The following commands will also be influenced by the  state  of  the
             global 'B' (bold disable) toggle.
    
             ?b? :Bold/Reverse_toggle
                  This  command  will  impact how the 'x' and 'y' toggles are dis-
                  played.  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.  You probably
                  don't need a constant visual reminder of the sort field and  top
                  hopes  that  you  always run with 'column highlight' Off, due to
                  the cost in path-length.
    
                  If you forget which field is being sorted this command can serve
                  as a quick visual reminder.
    
             ?y? :Row_Highlight_toggle
                  Changes   highlighting  for  "running"  tasks.   For  additional
                  insight into this task state,  see  topic  2a.  DESCRIPTIONS  of
                  Fields, Process Status.
    
                  Use  of this provision provides important insight into your sys-
                  tem'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
    
             ?H? :Threads_toggle
                  When  this  toggle  is  On,  all individual threads will be dis-
                  played.  Otherwise, top displays a summation of all threads in a
                  process.
    
             ?S? :Cumulative_Time_Mode_toggle
                  When  'Cumulative  mode'  is On, each process is listed with the
                  cpu time that it and its dead children have used.
    
                  When Off, programs that  fork  into  many  separate  tasks  will
                  appear less demanding.  For programs like 'init' or a shell this
                  is appropriate but for  others,  like  compilers,  perhaps  not.
                  Experiment with two task windows sharing the same sort field but
                  with different 'S' states and see which representation you  pre-
                  fer.
    
                  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? :Show_Specific_User_Only
                  You will be prompted to enter the name of the user  to  display.
                  Thereafter,  in that task window only matching User ID's will be
                  shown, or possibly no tasks will be shown.
    
                  Later, if you wish to monitor all  tasks  again,  re-issue  this
                  command  but just press <Enter> at the prompt, without providing
                  a name.
    
           SIZE of task window
             ?i? :Idle_Processes_toggle
                  Displays all tasks or just active tasks.  When  this  toggle  is
                  Off, idled or zombied processes will not be displayed.
    
                  If  this  command  is  applied  to the last task display when in
                  alternate-display mode, then it will  not  affect  the  window's
                  size, as all prior task displays will have already been painted.
    
             ?n? or ?#? :Set_Maximum_Tasks
                  You will be prompted to enter the number of  tasks  to  display.
                  The  lessor  of  your  number  and available screen rows will be
                  used.
    
                  When used in alternate-display mode, this is  the  command  that
                  gives  you precise control over the size of each currently visi-
                  ble task display, except for the very last.  It will not  affect
                  the  last  window's  size,  as all prior task displays will have
                  already been painted.
    
                  Note: If you wish to increase the size of the last visible  task
    
             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 cur-
             rent sort field is visible.  The sort  field  might  not  be  visible
             because:
                  1) there is insufficient Screen Width
                  2) the 'f' interactive command turned it Off
    
             ?<? :Move_Sort_Field_Left
                  Moves  the sort column to the left unless the current sort field
                  is the first field being displayed.
    
             ?>? :Move_Sort_Field_Right
                  Moves the sort column to the right unless the current sort field
                  is the last field being displayed.
    
             The  following interactive commands will always be honored whether or
             not the current sort field is visible.
    
             ?F? or ?O? :Select_Sort_Field
                  These keys display a separate screen where you can change  which
                  field is used as the sort column.
    
                  If a field is selected which was not previously being displayed,
                  it will be forced On when you return to the top  display.   How-
                  ever,  depending  upon  your  screen width and the order of your
                  fields, this sort field may not be displayable.
    
                  This interactive command can be a convenient way to simply  ver-
                  ify  the  current sort field, when running top with column high-
                  lighting 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 dis-
             play.  Thus, the TTY and WCHAN fields will violate strict ASCII  col-
             lating sequence.
    
       3d. 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.
    
           Available interactive commands
               4 upper case letters to select a target
               8 numbers to select a color
    
           The  Color Mapping screen can also be used to change the ?current' win-
           dow/field group in either full-screen mode or  alternate-display  mode.
           Whatever was targeted when 'q' or <Enter> was pressed will be made cur-
           rent as you return to the top display.
    
    
    

    4. ALTERNATE-DISPLAY Mode

       4a. 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 com-
                  mand,  repeated below).  Each of the 4 field groups has a unique
                  separately configurable summary area and  its  own  configurable
                  task area.
    
                  In  alternate-display  mode, those 4 underlying field groups can
                  now be made visible simultaneously, or can be turned  Off  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.
    
       4b. COMMANDS for Windows
             ?-? and ?_? :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'  and  'o'  commands.   It
                  will  also  reflect  any  other task area options/toggles you've
                  applied yielding zero or more tasks.
    
                  The '_' key does the same  for  all  task  displays.   In  other
                  words, it switches between the currently visible task display(s)
                  and any task display(s) you had toggled Off.  If all 4 task dis-
                  plays are currently visible, this interactive command will leave
                  the summary area as the only display element.
    
                  The first time you issue this command, all  four  task  displays
                  will  be  shown.  Thereafter when you switch modes, you will see
                  only the task display(s) you've chosen to make visible.
    
           * ?a? and ?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 cir-
                  cular 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  empha-
                  sis/color,  that's  a  reminder the task display is Off and many
                  commands will be restricted.
    
           * ?G? :Choose_Another_Window/Field_Group
                  You will be prompted to enter a number between 1 and 4 designat-
                  ing  the  window/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  ?cur-
                  rent' window.  It does not require that the window name be visi-
                  ble (the 'l' toggle to be On).
    
           *  The interactive commands shown  with  an  asterisk  ('*')  have  use
              beyond alternate-display mode.
                  ?=', 'A', 'G'  are always available
                  ?a', 'w'       act the same when color mapping
    
    
    

    5. FILES

       5a. SYSTEM Configuration File
           The  presence  of  this file will influence which version of the 'help'
           screen is shown to an ordinary user.  More importantly, it  will  limit
           what  ordinary  users are allowed to do when top is running.  They will
           not be able to issue the following commands.
              k         Kill a task
              r         Renice a task
              d or s    Change delay/sleep interval
    
           The system configuration file is not created by top.  Rather, you  cre-
           ate  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
    
           sonal  configuration  file to the current directory, subject to permis-
           sions.
    
    
    

    6. 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.
    
       6a. Kernel Magic
           For these stupid tricks, top needs full-screen mode.
    
           -*-  The  user  interface,  through  prompts  and  help,  intentionally
                implies  that the delay interval is limited to tenths of a second.
                However, you're free to set any desired delay.  If you want to see
                Linux  at his scheduling best, try a delay of .09 seconds or less.
    
                For this experiment, under x-windows open an  xterm  and  maximize
                it.  Then do the following:
                  . provide a scheduling boost and tiny delay via:
                      nice -n -10 top -d.09
                  . keep sorted column highlighting Off to minimize
                    path length
                  . turn On reverse row highlighting for emphasis
                  . try various sort columns (TIME/MEM work well),
                    and normal or reverse sorts to bring the most
                    active processes into view
    
                What  you'll  see is a very busy Linux doing what he's always done
                for you, but there was no program available to illustrate this.
    
           -*-  Under an xterm using 'white-on-black' colors,  try  setting  top's
                task  color  to black and be sure that task highlighting is set to
                bold, not reverse.  Then set the delay interval to around .3  sec-
                onds.
    
                After  bringing  the  most active processes into view, what you'll
                see are the ghostly images of just the currently running tasks.
    
           -*-  Delete the existing rcfile, or create a new symlink.   Start  this
                new  version  then type 'T' (a secret key, see topic 3c. 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 for-
                mer 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.
    
       6b. Bouncing Windows
           For these stupid tricks, top needs alternate-display mode.
    
           This stupid trick also requires alternate-display mode.
    
           -*-  Display  all  4  windows and make sure that 1:Def is the ?current'
                window.  Then, keep increasing window size until the all the other
                task displays are "pushed out of the nest".
    
                When they've all been displaced, toggle between all visible/invis-
                ible windows.  Then ponder this:
                   is top fibbing or telling honestly your imposed truth?
    
    
    

    7. BUGS

           Send bug reports to:
              Albert D. Cahalan, <albert@users.sf.net>
    
           The top command calculates Cpu(s) by looking at the change in CPU  time
           values  between samples. When you first run it, it has no previous sam-
           ple to compare to, so these initial values are  the  percentages  since
           boot.  It  means you need at least two loops or you have to ignore sum-
           mary output from the first loop.  This is problem for example for batch
           mode.  There is a possible workaround if you define the CPULOOP=1 envi-
           ronment variable. The top command will be run one extra hidden loop for
           CPU data before standard output.
    
    
    

    8. HISTORY Former top

           The   original  top  was  written  by  Roger  Binns,  based  on  Branko
           Lankester's <lankeste@fwi.uva.nl> ps program.
    
           Robert Nation <nation@rocket.sanders.lockheed.com> adapted it  for  the
           proc file system.
    
           Helmut  Geyer  <Helmut.Geyer@iwr.uni-heidelberg.de>  added  support for
           configurable fields.
    
           Plus many other individuals contributed over the years.
    
    
    

    9. AUTHOR

           This entirely new and enhanced replacement was written by:
              Jim / James C. Warner, <warnerjc@worldnet.att.net>
    
           With invaluable help from:
              Albert D. Cahalan, <albert@users.sf.net>
              Craig Small, <csmall@small.dropbear.id.au>
    
    
    

    10. SEE ALSO

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