# top

## NAME



           top - display Linux processes
    


## SYNOPSIS



           **top**[_option_ ...]
    


## DESCRIPTION



           The **top** program provides a dynamic real-time view of a running
           system.  It can display **system** summary information as well as a
           list of **processes** or **threads** currently being managed by the Linux
           kernel.  The types of system summary information shown and the
           types, order and size of information displayed for processes are
           all user configurable and that configuration can be made
           persistent across restarts.
    
           The program provides a limited interactive interface for process
           manipulation as well as a much more extensive interface for
           personal configuration  --  encompassing every aspect of its
           operation.  And while **top** is referred to throughout this document,
           you are free to name the program anything you wish.  That new
           name, possibly an alias, will then be reflected on top's display
           and used when reading and writing a configuration file.
    


## OVERVIEW



       **Documentation**
           The remaining Table of Contents
    
               OVERVIEW
                  Operation
                  Linux Memory Types
               1. COMMAND-LINE Options
               2. SUMMARY Display
                  a. UPTIME and LOAD Averages
                  b. TASK and CPU States
                  c. MEMORY Usage
               3. FIELDS / Columns Display
                  a. DESCRIPTIONS of Fields
                  b. MANAGING Fields
               4. INTERACTIVE Commands
                  a. GLOBAL Commands
                  b. SUMMARY AREA Commands
                  c. TASK AREA Commands
                     1. Appearance
                     2. Content
                     3. Size
                     4. Sorting
                  d. BOTTOM WINDOW Commands
                  e. COLOR Mapping
               5. ALTERNATE-DISPLAY Provisions
                  a. WINDOWS Overview
                  b. COMMANDS for Windows
                  c. SCROLLING a Window
                  d. SEARCHING in a Window
                  e. FILTERING in a Window
               6. FILES
                  a. PERSONAL Configuration File
                  b. ADDING INSPECT Entries
                  c. SYSTEM Configuration File
                  d. SYSTEM Restrictions File
               7. ENVIRONMENT VARIABLE(S)
               8. STUPID TRICKS Sampler
                  a. Kernel Magic
                  b. Bouncing Windows
                  c. The Big Bird Window
                  d. The Ol' Switcheroo
               9. BUGS, 10. SEE Also
    
       **Operation**
           When operating top, the two most important keys are the help (h or
           ?)  key and quit (‘q’) key.  Alternatively, you could simply use
           the traditional interrupt key (^C) when you're done.
    
           When started for the first time, you'll be presented with these
           traditional elements on the main top screen: 1) Summary Area; 2)
           Fields/Columns Header; 3) Task Area.  Each of these will be
           explored in the sections that follow.  There is also an
           Input/Message line between the Summary Area and Columns Header
           which needs no further explanation.
    
           The main top screen is _generally_ quite adaptive to changes in
           terminal dimensions under X-Windows.  Other top screens may be
           less so, especially those with static text.  It ultimately
           depends, however, on your particular window manager and terminal
           emulator.  There may be occasions when their view of terminal size
           and current contents differs from top's view, which is always
           based on operating system calls.
    
           Following any re-size operation, if a top screen is corrupted,
           appears incomplete or disordered, simply typing something
           innocuous like a punctuation character or cursor motion key will
           usually restore it.  In extreme cases, the following sequence
           almost certainly will:
                  _key/cmd_  _objective_
                  ^Z       **suspend** top
                  fg       **resume** top
                  <Left>   force a screen **redraw**(if necessary)
    
           But if the display is still corrupted, there is one more step you
           could try.  Insert this command after top has been suspended but
           before resuming it.
                  _key/cmd_  _objective_
                  reset    restore your **terminal settings**
    
           **Note** : the width of top's display will be limited to 512 positions.
           Displaying all fields requires approximately 250 characters.
           Remaining screen width is usually allocated to any variable width
           columns currently visible.  The variable width columns, such as
           COMMAND, are noted in topic 3a. DESCRIPTIONS of Fields.  Actual
           output width may also be influenced by the -w switch, which is
           discussed in topic 1. COMMAND-LINE Options.
    
           Lastly, some of top's screens or functions require the use of
           cursor motion keys like the standard arrow keys plus the Home,
           End, PgUp and PgDn keys.  If your terminal or emulator does not
           provide those keys, the following combinations are accepted as
           alternatives:
                  _key_      _equivalent-keys_
                  Left     alt + **h**
                  Down     alt + **j**
                  Up       alt + **k**
                  Right    alt + **l**
                  Home     alt + ctrl + **h**
                  PgDn     alt + ctrl + **j**
                  PgUp     alt + ctrl + **k**
                  End      alt + ctrl + **l**
    
           The **Up** and **Down** arrow keys have special significance when prompted
           for line input terminated with the <Enter> key.  Those keys, or
           their aliases, can be used to retrieve previous input lines which
           can then be edited and re-input.  And there are four additional
           keys available with line oriented input.
                  _key_      _special-significance_
                  Up       recall **older** strings for re-editing
                  Down     recall **newer** strings or **erase** entire line
                  Insert   toggle between **insert** and **overtype** modes
                  Delete   character **removed** at cursor, moving others left
                  Home     jump to **beginning** of input line
                  End      jump to **end** of input line
    
       **Linux Memory Types**
           For our purposes there are three types of memory, and one is
           optional.  First is physical memory, a limited resource where code
           and data must reside when executed or referenced.  Next is the
           optional swap file, where modified (dirty) memory can be saved and
           later retrieved if too many demands are made on physical memory.
           Lastly we have virtual memory, a nearly unlimited resource serving
           the following goals:
    
              1. abstraction, free from physical memory addresses/limits
              2. isolation, every process in a separate address space
              3. sharing, a single mapping can serve multiple needs
              4. flexibility, assign a virtual address to a file
    
           Regardless of which of these forms memory may take, all are
           managed as pages (typically 4096 bytes) but expressed by default
           in top as KiB (kibibyte).  The memory discussed under topic ‘2c.
           MEMORY Usage’ deals with physical memory and the swap file for the
           system as a whole.  The memory reviewed in topic ‘3. FIELDS /
           Columns Display’ embraces all three memory types, but for
           individual processes.
    
           For each such process, every memory page is restricted to a single
           quadrant from the table below.  Both physical memory and virtual
           memory can include any of the four, while the swap file only
           includes #1 through #3.  The memory in quadrant #4, when modified,
           acts as its own dedicated swap file.
    
                                         **Private** | **Shared**
                                     **1** |          **2**
                **Anonymous**. stack               |
                           . malloc()            |
                           . brk()/sbrk()        | . POSIX shm*
                           . mmap(PRIVATE, ANON) | . mmap(SHARED, ANON)
                          -----------------------+----------------------
                           . mmap(PRIVATE, fd)   | . mmap(SHARED, fd)
              **File-backed**. pgms/shared libs    |
                                     **3** |          **4**
    
           The following may help in interpreting process level memory values
           displayed as scalable columns and discussed under topic ‘3a.
           DESCRIPTIONS of Fields’.
    
              %MEM - simply RES divided by total physical memory
              CODE - the ‘pgms’ portion of quadrant **3**
              DATA - the entire quadrant **1** portion of VIRT plus all
                     explicit mmap file-backed pages of quadrant **3**
              RES  - anything occupying physical memory which, beginning with
                     Linux-4.5, is the sum of the following three fields:
                     RSan - quadrant **1** pages, which include any
                            former quadrant **3** pages if modified
                     RSfd - quadrant **3** and quadrant **4** pages
                     RSsh - quadrant **2** pages
              RSlk - subset of RES which cannot be swapped out (any quadrant)
              SHR  - subset of RES (excludes **1** , includes all **2** & **4** , some **3**)
              SWAP - potentially any quadrant except **4**
              USED - simply the sum of RES and SWAP
              VIRT - everything in-use and/or reserved (all quadrants)
    
           **Note** : Even though program images and shared libraries are
           considered _private_ to a process, they will be accounted for as
           _shared_ (SHR) by the kernel.
    


## 1\. COMMAND-LINE Options



           Mandatory _arguments_ to long options are mandatory for short
           options too.
    
           Although not required, the equals sign can be used with either
           option form and whitespace before and/or after the ‘=’ is
           permitted.
    
           -**A** , **--apply-defaults**
              Run top with build defaults only, ignoring all configuration
              files except /etc/toprc.  This option, when specified, must be
              the only command line option present.
    
           -**b** , **--batch**
              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** , **--cmdline-toggle**
              Starts top with the last remembered ‘c’ state reversed.  Thus,
              if top was displaying command lines, now that field will show
              program names, and vice versa.  See the ‘c’ interactive command
              for additional information.
    
           -**d** , **--delay** = _SECS_ [_.TENTHS_]
              Specifies the delay between screen updates, and overrides the
              corresponding value in one's personal configuration file or the
              startup default.  Later this can be changed with the ‘d’ or ‘s’
              interactive commands.
    
              Fractional seconds are honored, but a negative number is not
              allowed.  In all cases, however, such changes are prohibited if
              top is running in Secure mode, except for root (unless the ‘s’
              command-line option was used).  For additional information on
              Secure mode see topic 6d. SYSTEM Restrictions File.
    
           -**E** , **--scale-summary-mem** = _k_ | _m_ | _g_ | _t_ | _p_ | _e_
              Instructs top to force summary area memory to be scaled as:
                 k - kibibytes
                 m - mebibytes
                 g - gibibytes
                 t - tebibytes
                 p - pebibytes
                 e - exbibytes
    
              Later this can be changed with the ‘E’ command toggle.
    
           -**e** , **--scale-task-mem** = _k_ | _m_ | _g_ | _t_ | _p_
              Instructs top to force task area memory to be scaled as:
                 k - kibibytes
                 m - mebibytes
                 g - gibibytes
                 t - tebibytes
                 p - pebibytes
    
              Later this can be changed with the ‘e’ command toggle.
    
           -**H** , **--threads-show**
              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.
    
           -**h** , **--help**
              Display usage help text, then quit.
    
           -**i** , **--idle-toggle**
              Starts top with the last remembered ‘i’ state reversed.  When
              this toggle is _Off_ , tasks that have not used any CPU since the
              last update will not be displayed.  For additional information
              regarding this toggle see topic 4c. TASK AREA Commands, SIZE.
    
           -**n** , **--iterations** = _NUMBER_
              Specifies the maximum number of iterations, or frames, top
              should produce before ending.
    
           -**O** , **--list-fields**
              This option acts as a form of help for the -o option shown
              below.  It will cause top to print each of the available field
              names on a separate line, then quit.  Such names are subject to
              NLS (National Language Support) translation.
    
           -**o** , **--sort-override** = _FIELDNAME_
              Specifies the name of the field on which tasks will be sorted,
              independent of what is reflected in the configuration file.
              You can prepend a ‘+’ or ‘-’ to the field name to also override
              the sort direction.  A leading ‘+’ will force sorting high to
              low, whereas a ‘-’ will ensure a low to high ordering.
    
              This option exists primarily to support automated/scripted
              batch mode operation.
    
           -**p** , **--pid** = _PIDLIST_ (as: _1_ ,_2_ ,_3_ , ... or
              -p _1_ -p _2_ -p _3_ ...)  Monitor only processes with specified process
              IDs.  However, when combined with Threads mode (‘H’), all
              processes in the thread group (see TGID) of each monitored PID
              will also be shown.
    
              This option can be given up to 20 times, or you can provide a
              comma delimited list with up to 20 pids.  Co-mingling both
              approaches is permitted.
    
              A pid value of zero will be treated as the process id of the
              top program itself once it is running.
    
              This is a command-line option only and should you wish to
              return to normal operation, it is not necessary to quit and
              restart top  --  just issue any of these interactive commands:
              ‘=’, ‘u’ or ‘U’.
    
              The ‘p’, ‘u’ and ‘U’ command-line options are mutually
              exclusive.
    
           -**S** , **--accum-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.
    
           -**s** , **--secure-mode**
              Starts top with secure mode forced, even for root.  This mode
              is far better controlled through a system configuration file
              (see topic 6. FILES).
    
           -**U** , **--filter-any-user** = _USER_ (as: _number_ or _name_)
              Display only processes with a user id or user name matching
              that given.  This option matches on _any_ user (_real_ , _effective_ ,
              _saved_ , or _filesystem_).
    
              Prepending an exclamation point (‘!’) to the user id or name
              instructs top to display only processes with users not matching
              the one provided.
    
              The ‘p’, ‘U’ and ‘u’ command-line options are mutually
              exclusive.
    
           -**u** , **--filter-only-euser** = _USER_ (as: _number_ or _name_)
              Display only processes with a user id or user name matching
              that given.  This option matches on the _effective_ user id only.
    
              Prepending an exclamation point (‘!’) to the user id or name
              instructs top to display only processes with users not matching
              the one provided.
    
              The ‘p’, ‘U’ and ‘u’ command-line options are mutually
              exclusive.
    
           -**V** , **--version**
              Display version information, then quit.
    
           -**w** , **--width**[=_COLUMNS_]
              In Batch mode, when used without an argument top will format
              output using the COLUMNS= and LINES= environment variables, if
              set.  Otherwise, width will be fixed at the maximum 512
              columns.  With an argument, output width can be decreased or
              increased (up to 512) but the number of rows is considered
              unlimited.
    
              In normal display mode, when used without an argument top will
              _attempt_ to format output using the COLUMNS= and LINES=
              environment variables, if set.  With an argument, output width
              can only be decreased, not increased.  Whether using
              environment variables or an argument with -w, when _not_ in Batch
              mode actual terminal dimensions can never be exceeded.
    
              **Note** : Without the use of this command-line option, output width
              is always based on the terminal at which top was invoked
              whether or not in Batch mode.
    
           -**1** , **--single-cpu-toggle**
              Starts top with the last remembered Cpu States portion of the
              summary area reversed.  Either all cpu information will be
              displayed in a single line or each cpu will be displayed
              separately, depending on the state of the NUMA Node command
              toggle (‘2’).
    
              See the ‘1’ and ‘2’ interactive commands for additional
              information.
    


## 2\. SUMMARY Display



           Each of the following three areas are individually controlled
           through one or more interactive commands.  See topic 4b. SUMMARY
           AREA Commands for additional information regarding these
           provisions.
    
       **2a. UPTIME and LOAD Averages**
           This portion consists of a single line containing:
               **program** or **window** name, depending on display mode
               current time and length of time since last boot
               total number of users
               system load avg over the last 1, 5 and 15 minutes
    
       **2b. TASK and CPU States**
           This portion consists of a minimum of two lines.  In an SMP
           environment, additional lines can reflect individual CPU state
           percentages.
    
           Line 1 shows total **tasks** or **threads** , depending on the state of the
           Threads-mode toggle.  That total is further classified according
           to task state as follows:
               displayed       process status (‘S’)
               ---------       --------------------
               running         R
               sleep           S + any remaining
               d-sleep         D
               stopped         T + t
               zombie          Z
    
           Line 2 shows CPU state percentages based on the interval since the
           last refresh.
    
           As a default, percentages for these individual categories are
           displayed.  Depending on your kernel version, the **st** field may not
           be shown.
               **us** : time running un-niced user processes
               **sy** : time running kernel processes
               **ni** : time running niced user processes
               **id** : time spent in the kernel idle handler
               **wa** : 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
    
           Beyond the first tasks/threads line, there are alternate CPU
           display modes available via the 4-way ‘t’ command toggle.  They
           show an abbreviated summary consisting of these elements:
                          a    b     c    d
               %Cpu(s):  **75.0** /25.0  **100**[ ... ]
    
           Where: a) is the ‘user’ (us + ni) percentage; b) is the ‘system’
           (sy + hi + si + guests) percentage; c) is the total percentage;
           and d) is one of two visual graphs of those representations.  Such
           graphs also reflect separate ‘user’ and ‘system’ portions.
    
           If the ‘4’ command toggle is used to yield more than two cpus per
           line, results will be further abridged eliminating the a) and b)
           elements.  However, that information is still reflected in the
           graph itself assuming color is active or, if not, bars vs. blocks
           are being shown.
    
           See topic 4b. SUMMARY AREA Commands for additional information on
           the ‘t’ and ‘4’ command toggles.
    
       **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. The
           /proc/meminfo source fields are shown in parenthesis.
    
           Line 1 reflects physical memory, classified as:
               total          ( MemTotal )
               free           ( MemFree )
               used           ( MemTotal - MemAvailable )
               buff/cache     ( Buffers + Cached + SReclaimable )
    
           Line 2 reflects mostly virtual memory, classified as:
               total          ( SwapTotal )
               free           ( SwapFree )
               used           ( SwapTotal - SwapFree )
               avail          ( MemAvailable, which is physical memory )
    
           The **avail** number on line 2 is an estimation of physical memory
           available for starting new applications, without swapping.  Unlike
           the **free** field, it attempts to account for readily reclaimable
           page cache and memory slabs.  It is available on kernels 3.14,
           emulated on kernels 2.6.27+, otherwise the same as **free**.
    
           In the alternate memory display modes, two abbreviated summary
           lines are shown consisting of these elements:
                          a    b          c
               GiB Mem : **18.7** /15.738   [ ... ]
               GiB Swap:  **0.0** /7.999    [ ... ]
    
           Where: a) is the percentage used; b) is the total available; and
           c) is one of two visual graphs of those representations.
    
           In the case of physical memory, the percentage represents the
           **total** minus the estimated **avail** noted above.  The ‘Mem’ graph
           itself is divided between the non-cached portion of **used** and any
           remaining memory not otherwise accounted for by **avail**.  See topic
           4b. SUMMARY AREA Commands and the ‘m’ command for additional
           information on that special 4-way toggle.
    
           This table may help in interpreting the scaled values displayed:
               KiB = kibibyte = 1024 bytes
               MiB = mebibyte = 1024 KiB = 1,048,576 bytes
               GiB = gibibyte = 1024 MiB = 1,073,741,824 bytes
               TiB = tebibyte = 1024 GiB = 1,099,511,627,776 bytes
               PiB = pebibyte = 1024 TiB = 1,125,899,906,842,624 bytes
               EiB = exbibyte = 1024 PiB = 1,152,921,504,606,846,976 bytes
    


## 3\. FIELDS / Columns



       **3a. DESCRIPTIONS of Fields**
           Listed below are top's available process fields (columns).  They
           are shown in strict ascii alphabetical order.  You may customize
           their position and whether or not they are displayable with the
           ‘f’ (Fields Management) 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 4c. TASK AREA Commands,
           SORTING.
    
           The fields related to physical memory or virtual memory reference
           ‘(KiB)’ which is the unsuffixed display mode.  Such fields may,
           however, be scaled from KiB through PiB.  That scaling is
           influenced via the ‘e’ interactive command or established for
           startup through a build option.
    
           **%CPU** --  CPU Usage
               The task's share of the elapsed CPU time since the last screen
               update, expressed as a percentage of total CPU time.
    
               In a true SMP environment, if a process is multi-threaded and
               top is _not_ operating in Threads mode, amounts greater than
               100% may be reported.  You toggle Threads mode with the ‘H’
               interactive command.
    
               Also for multi-processor environments, if Irix mode is _Off_ ,
               top will operate in Solaris mode where a task's cpu usage will
               be divided by the total number of CPUs.  You toggle
               Irix/Solaris modes with the ‘I’ interactive command.
    
               **Note** : When running in forest view mode (‘V’) with children
               collapsed (‘v’), this field will also include the CPU time of
               those unseen children.  See topic 4c. TASK AREA Commands,
               CONTENT for more information regarding the ‘V’ and ‘v’
               toggles.
    
           **%CUC** --  CPU Utilization
               This field is identical to %CUU below, except the percentage
               also reflects reaped child processes.
    
           **%CUU** --  CPU Utilization
               A task's total CPU usage divided by its elapsed running time,
               expressed as a percentage.
    
               If a process currently displays high CPU usage, this field can
               help determine if such behavior is normal.  Conversely, if a
               process has low CPU usage currently, %CUU may reflect
               historically higher demands over its lifetime.
    
           **%MEM** --  Memory Usage (RES)
               A task's currently resident share of available physical
               memory.
    
               See ‘OVERVIEW, Linux Memory Types’ for additional details.
    
           **AGID** --  Autogroup Identifier
               The autogroup identifier associated with a process.  This
               feature operates in conjunction with the CFS scheduler to
               improve interactive desktop performance.
    
               When /proc/sys/kernel/sched_autogroup_enabled is set, a new
               autogroup is created with each new session (see SID).  All
               subsequently forked processes in that session inherit
               membership in this autogroup.  The kernel then attempts to
               equalize distribution of CPU cycles across such groups.  Thus,
               an autogroup with many CPU intensive processes (e.g make -j)
               will not dominate an autogroup with only one or two processes.
    
               When -1 is displayed it means this information is not
               available.
    
           **AGNI** --  Autogroup Nice Value
               The autogroup nice value which affects scheduling of all
               processes in that group.  A negative nice value means higher
               priority, whereas a positive nice value means lower priority.
    
           **CGNAME** --  Control Group Name
               The name of the control group to which a process belongs, or
               ‘-’ if not applicable for that process.
    
               Available with cgroup v1 only, this will typically be the last
               entry in the full list of control groups as displayed under
               the CGROUPS heading.  And as is true there, this field is also
               variable width.
    
           **CGROUPS** --  Control Groups
               The names of the control group(s) to which a process belongs,
               or ‘-’ if not applicable for that process.
    
               Control Groups provide for allocating resources (cpu, memory,
               network bandwidth, etc.) among installation-defined groups of
               processes.  They enable fine-grained control over allocating,
               denying, prioritizing, managing and monitoring those
               resources.
    
               Many different hierarchies of cgroups can exist simultaneously
               on a system and each hierarchy is attached to one or more
               subsystems.  A subsystem represents a single resource.
    
               **Note** : The CGROUPS field, unlike most columns, is not fixed-
               width.  When displayed, it plus any other variable width
               columns will be allocated all remaining screen width (up to
               the maximum 512 characters).  Even so, such variable width
               fields could still suffer truncation.  See topic 5c. SCROLLING
               a Window for additional information on accessing any truncated
               data.
    
           **CLS** --  Scheduling Class
               The task's current scheduling policy which can be one of:
                   **-** = not reported
                   **TS** = SCHED_OTHER
                   **FF** = SCHED_FIFO
                   **RR** = SCHED_RR
                   **B** = SCHED_BATCH
                   **ISO** = SCHED_ISO
                   **IDL** = SCHED_IDLE
                   **DLN** = SCHED_DEADLINE
                   **?** = unknown value
    
           **CODE** --  Code Size (KiB)
               The amount of physical memory currently devoted to executable
               code, also known as the Text Resident Set size or TRS.
    
               See ‘OVERVIEW, Linux Memory Types’ for additional details.
    
           **COMMAND** --  Command **Name** or Command **Line**
               Display the command line used to start a task or the name of
               the associated program.  You toggle between command _line_ and
               _name_ with ‘c’, which is both a command-line option and an
               interactive command.
    
               When you've chosen to display command lines, processes without
               a command line (like kernel threads) will be shown with only
               the program name in brackets, as in this example:
                   [kthreadd]
    
               This field may also be impacted by the forest view display
               mode.  See the ‘V’ interactive command for additional
               information regarding that mode.
    
               **Note** : The COMMAND field, unlike most columns, is not fixed-
               width.  When displayed, it plus any other variable width
               columns will be allocated all remaining screen width (up to
               the maximum 512 characters).  Even so, such variable width
               fields could still suffer truncation.  This is especially true
               for this field when command lines are being displayed (the ‘c’
               interactive command.)  See topic 5c. SCROLLING a Window for
               additional information on accessing any truncated data.
    
           **DATA** --  Data + Stack Size (KiB)
               The amount of private memory _reserved_ by a process.  It is
               also known as the Data Resident Set or DRS.  Such memory may
               not yet be mapped to physical memory (RES) but will always be
               included in the virtual memory (VIRT) amount.
    
               See ‘OVERVIEW, Linux Memory Types’ for additional details.
    
           **Docker** --  Docker Container ID
               The identity (abbreviated hash) of the docker container within
               which a task is running.  If a process is not running inside a
               container, a dash (‘-’) will be shown.
    
           **ELAPSED** --  Elapsed Running Time
               The length of time since a process was started.  Thus, the
               most recently started task will display the smallest time
               interval.
    
               The value will be expressed as ‘HH,MM’ (hours,minutes) but is
               subject to additional scaling if the interval becomes too
               great to fit column width.  At that point it will be scaled to
               ‘DD+HH’ (days+hours) and possibly beyond.
    
           **ENVIRON** --  Environment variables
               Display all of the environment variables, if any, as seen by
               the respective processes.  These variables will be displayed
               in their raw native order, not the sorted order you are
               accustomed to seeing with an unqualified ‘set’.
    
               **Note** : The ENVIRON field, unlike most columns, is not fixed-
               width.  When displayed, it plus any other variable width
               columns will be allocated all remaining screen width (up to
               the maximum 512 characters).  Even so, such variable width
               fields could still suffer truncation.  This is especially true
               for this field.  See topic 5c. SCROLLING a Window for
               additional information on accessing any truncated data.
    
           **EXE** --  Executable Path
               Where available, this is the full path to the executable,
               including the program name.
    
               **Note** : The EXE field, unlike most columns, is not fixed-width.
               When displayed, it plus any other variable width columns will
               be allocated all remaining screen width (up to the maximum 512
               characters).
    
           **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>.
    
           **GID** --  Group Id
               The _effective_ group ID.
    
           **GROUP** --  Group Name
               The _effective_ group name.
    
           **LOGID** --  Login User Id
               The user ID used at _login_.  When -1 is displayed it means this
               information is not available.
    
           **LXC** --  Lxc Container Name
               The name of the lxc container within which a task is running.
               If a process is not running inside a container, a dash (‘-’)
               will be shown.
    
           **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.
    
               **Note** : This value only affects scheduling priority relative to
               other processes in the same autogroup.  See the ‘AGID’ and
               ‘AGNI’ fields for additional information on autogroups.
    
           **NU** --  Last known NUMA node
               A number representing the NUMA node associated with the last
               used processor (‘P’).  When -1 is displayed it means that NUMA
               information is not available.
    
               See the ‘2’ and ‘3’ interactive commands for additional NUMA
               provisions affecting the summary area.
    
           **OOMa** --  Out of Memory Adjustment Factor
               The value, ranging from -1000 to +1000, added to the current
               out of memory score (OOMs) which is then used to determine
               which task to kill when memory is exhausted.
    
           **OOMs** --  Out of Memory Score
               The value, ranging from 0 to +1000, used to select task(s) to
               kill when memory is exhausted.  Zero translates to ‘never
               kill’ whereas 1000 means ‘always kill’.
    
           **P** --  Last used CPU (SMP)
               A number representing the last used processor.  In a true SMP
               environment this will likely change frequently since the
               kernel intentionally uses weak affinity.  Also, the very act
               of running top may break this weak affinity and cause more
               processes to change CPUs more often (because of the extra
               demand for cpu time).
    
           **PGRP** --  Process Group Id
               Every process is member of a unique process group which is
               used for distribution of signals and by terminals to arbitrate
               requests for their input and output.  When a process is
               created (forked), it becomes a member of the process group of
               its parent.  By convention, this value equals the process ID
               (see PID) of the first member of a process group, called the
               process group leader.
    
           **PID** --  Process Id
               The task's unique process ID, which periodically wraps, though
               never restarting at zero.  In kernel terms, it is a
               dispatchable entity defined by a task_struct.
    
               This value may also be used as: a process group ID (see PGRP);
               a session ID for the session leader (see SID); a thread group
               ID for the thread group leader (see TGID); and a TTY process
               group ID for the process group leader (see TPGID).
    
           **PPID** --  Parent Process Id
               The process ID (pid) of a task's parent.
    
           **PR** --  Priority
               The scheduling priority of the task.  If you see ‘rt’ in this
               field, it means the task is running under real time scheduling
               priority.
    
               Under linux, real time priority is somewhat misleading since
               traditionally the operating itself was not preemptible.  And
               while the 2.6 kernel can be made mostly preemptible, it is not
               always so.
    
           **PSS** --  Proportional Resident Memory, smaps (KiB)
               The proportion of this task's share of ‘RSS’ where each page
               is divided by the number of processes sharing it.  It is also
               the sum of the ‘PSan’, ‘PSfd’ and ‘PSsh’ fields.
    
               For example, if a process has 1000 resident pages alone and
               1000 resident pages shared with another process, its ‘PSS’
               would be 1500 (times page size).
    
               Accessing smaps values is 10x more costly than other memory
               statistics and data for other users requires root privileges.
    
           **PSan** --  Proportional Anonymous Memory, smaps (KiB)
           **PSfd** --  Proportional File Memory, smaps (KiB)
           **PSsh** --  Proportional Shmem Memory, smaps (KiB)
               As was true for ‘PSS’ above (total proportional resident
               memory), these fields represent the proportion of this task's
               share of each type of memory divided by the number of
               processes sharing it.
    
               Accessing smaps values is 10x more costly than other memory
               statistics and data for other users requires root privileges.
    
           **RES** --  Resident Memory Size (KiB)
               A subset of the virtual address space (VIRT) representing the
               non-swapped physical memory a task is currently using.  It is
               also the sum of the ‘RSan’, ‘RSfd’ and ‘RSsh’ fields.
    
               It can include private anonymous pages, private pages mapped
               to files (including program images and shared libraries) plus
               shared anonymous pages.  All such memory is backed by the swap
               file represented separately under SWAP.
    
               Lastly, this field may also include shared file-backed pages
               which, when modified, act as a dedicated swap file and thus
               will never impact SWAP.
    
               See ‘OVERVIEW, Linux Memory Types’ for additional details.
    
           **RSS** --  Resident Memory, smaps (KiB)
               Another, more precise view of process non-swapped physical
               memory.  It is obtained from the ‘smaps_rollup’ file and is
               generally slightly larger than that shown for ‘RES’.
    
               Accessing smaps values is 10x more costly than other memory
               statistics and data for other users requires root privileges.
    
           **RSan** --  Resident Anonymous Memory Size (KiB)
               A subset of resident memory (RES) representing private pages
               not mapped to a file.
    
           **RSfd** --  Resident File-Backed Memory Size (KiB)
               A subset of resident memory (RES) representing the implicitly
               shared pages supporting program images and shared libraries.
               It also includes explicit file mappings, both private and
               shared.
    
           **RSlk** --  Resident Locked Memory Size (KiB)
               A subset of resident memory (RES) which cannot be swapped out.
    
           **RSsh** --  Resident Shared Memory Size (KiB)
               A subset of resident memory (RES) representing the explicitly
               shared anonymous shm*/mmap pages.
    
           **RUID** --  Real User Id
               The _real_ user ID.
    
           **RUSER** --  Real User Name
               The _real_ user name.
    
           **S** --  Process Status
               The status of the task which can be one of:
                   **D** = uninterruptible sleep
                   **I** = idle
                   **R** = running
                   **S** = sleeping
                   **T** = stopped by job control signal
                   **t** = stopped by debugger during trace
                   **Z** = zombie
    
               Tasks shown as running should be more properly thought of as
               ready to run  --  their task_struct is simply represented on
               the Linux run-queue.  Even without a true SMP machine, you may
               see numerous tasks in this state depending on top's delay
               interval and nice value.
    
           **SHR** --  Shared Memory Size (KiB)
               A subset of resident memory (RES) that may be used by other
               processes.  It will include shared anonymous pages and shared
               file-backed pages.  It also includes private pages mapped to
               files representing program images and shared libraries.
    
               See ‘OVERVIEW, Linux Memory Types’ for additional details.
    
           **SID** --  Session Id
               A session is a collection of process groups (see PGRP),
               usually established by the login shell.  A newly forked
               process joins the session of its creator.  By convention, this
               value equals the process ID (see PID) of the first member of
               the session, called the session leader, which is usually the
               login shell.
    
           **STARTED** --  Start Time Interval
               The length of time since system boot when a process started.
               Thus, the most recently started task will display the largest
               time interval.
    
               The value will be expressed as ‘MM:SS’ (minutes:seconds).  But
               if the interval is too great to fit column width it will be
               scaled as ‘HH,MM’ (hours,minutes) and possibly beyond.
    
           **SUID** --  Saved User Id
               The _saved_ user ID.
    
           **SUPGIDS** --  Supplementary Group IDs
               The IDs of any supplementary group(s) established at login or
               inherited from a task's parent.  They are displayed in a comma
               delimited list.
    
               **Note** : The SUPGIDS field, unlike most columns, is not fixed-
               width.  When displayed, it plus any other variable width
               columns will be allocated all remaining screen width (up to
               the maximum 512 characters).
    
           **SUPGRPS** --  Supplementary Group Names
               The names of any supplementary group(s) established at login
               or inherited from a task's parent.  They are displayed in a
               comma delimited list.
    
               **Note** : The SUPGRPS field, unlike most columns, is not fixed-
               width.  When displayed, it plus any other variable width
               columns will be allocated all remaining screen width (up to
               the maximum 512 characters).
    
           **SUSER** --  Saved User Name
               The _saved_ user name.
    
           **SWAP** --  Swapped Size (KiB)
               The formerly resident portion of a task's address space
               written to the swap file when physical memory becomes over
               committed.
    
               See ‘OVERVIEW, Linux Memory Types’ for additional details.
    
           **TGID** --  Thread Group Id
               The ID of the thread group to which a task belongs.  It is the
               PID of the thread group leader.  In kernel terms, it
               represents those tasks that share an mm_struct.
    
           **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.
    
           **TIME+** --  CPU Time, hundredths
               The same as TIME, but reflecting more granularity through
               hundredths of a second.
    
           **TPGID** --  Tty Process Group Id
               The process group ID of the foreground process for the
               connected tty, or -1 if a process is not connected to a
               terminal.  By convention, this value equals the process ID
               (see PID) of the process group leader (see PGRP).
    
           **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.
    
           **UID** --  User Id
               The _effective_ user ID of the task's owner.
    
           **USED** --  Memory in Use (KiB)
               This field represents the non-swapped physical memory a task
               is using (RES) plus the swapped out portion of its address
               space (SWAP).
    
               See ‘OVERVIEW, Linux Memory Types’ for additional details.
    
           **USER** --  User Name
               The _effective_ user name of the task's owner.
    
           **USS** --  Unique Set Size
               The non-swapped portion of physical memory (‘RSS’) not shared
               with any other process.  It is derived from the ‘smaps_rollup’
               file.
    
               Accessing smaps values is 10x more costly than other memory
               statistics and data for other users requires root privileges.
    
           **VIRT** --  Virtual Memory Size (KiB)
               The total amount of virtual memory used by the task.  It
               includes all code, data and shared libraries plus pages that
               have been swapped out and pages that have been mapped but not
               used.
    
               See ‘OVERVIEW, Linux Memory Types’ for additional details.
    
           **WCHAN** --  Sleeping in Function
               This field will show the name of the kernel function in which
               the task is currently sleeping.  Running tasks will display a
               dash (‘-’) in this column.
    
           **ioR** --  I/O Bytes Read
               The number of bytes a process caused to be fetched from the
               storage layer.
    
               Root privileges are required to display ‘io’ data for other
               users.
    
           **ioRop** --  I/O Read Operations
               The number of read I/O operations (syscalls) for a process.
               Such calls might not result in actual physical disk I/O.
    
           **ioW** --  I/O Bytes Written
               The number of bytes a process caused to be sent to the storage
               layer.
    
           **ioWop** --  I/O Write Operations
               The number of write I/O operations (syscalls) for a process.
               Such calls might not result in actual physical disk I/O.
    
           **nDRT** --  Dirty Pages Count
               The number of pages that have been modified since they were
               last written to auxiliary storage.  Dirty pages must be
               written to auxiliary storage before the corresponding physical
               memory location can be used for some other virtual page.
    
               This field was deprecated with linux 2.6 and is always zero.
    
           **nFD** --  Number of File Descriptors
               The total number of open files associated with a process.
    
           **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.
    
           **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.
    
           **nTH** --  Number of Threads
               The number of threads associated with a process.
    
           **nsCGROUP** --  CGROUP namespace
               The Inode of the namespace used to hide the identity of the
               control group of which process is a member.
    
           **nsIPC** --  IPC namespace
               The Inode of the namespace used to isolate interprocess
               communication (IPC) resources such as System V IPC objects and
               POSIX message queues.
    
           **nsMNT** --  MNT namespace
               The Inode of the namespace used to isolate filesystem mount
               points thus offering different views of the filesystem
               hierarchy.
    
           **nsNET** --  NET namespace
               The Inode of the namespace used to isolate resources such as
               network devices, IP addresses, IP routing, port numbers, etc.
    
           **nsPID** --  PID namespace
               The Inode of the namespace used to isolate process ID numbers
               meaning they need not remain unique.  Thus, each such
               namespace could have its own ‘init/systemd’ (PID #1) to manage
               various initialization tasks and reap orphaned child
               processes.
    
           **nsTIME** --  TIME namespace
               The Inode of the namespace which allows processes to see
               different system times in a way similar to the UTS namespace.
    
           **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.
    
           **nsUTS** --  UTS namespace
               The Inode of the namespace used to isolate hostname and NIS
               domain name.  UTS simply means "Unix Time-sharing System".
    
           **vMj** --  Major Page Fault Count Delta
               The number of **major** page faults that have occurred since the
               last update (see nMaj).
    
           **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’ (Fields Management) you
           will be presented with a screen showing: 1) the ‘current’ window
           name; 2) the designated sort field; 3) all fields in their current
           order along with descriptions.  Entries marked with an asterisk
           are the currently displayed fields, screen width permitting.
    
               •  As the on screen instructions indicate, you navigate among
                  the fields with the **Up** and **Down** arrow keys.  The PgUp,
                  PgDn, Home and End keys can also be used to quickly reach
                  the first or last available field.
    
               •  The **Right** arrow key selects a field for repositioning and
                  the **Left** arrow key or the <**Enter** > key commits that field's
                  placement.
    
               •  The ‘**d** ’ key or the <**Space** > bar toggles a field's display
                  status, and thus the presence or absence of the asterisk.
    
               •  The ‘**s** ’ key designates a field as the sort field.  See
                  topic 4c. TASK AREA Commands, SORTING for additional
                  information regarding your selection of a sort field.
    
               •  The ‘**a** ’ and ‘**w** ’ keys can be used to cycle through all
                  available windows and the ‘**q** ’ or <**Esc** > keys exit Fields
                  Management.
    
           The Fields Management screen can also be used to change the
           ‘current’ window/field group in either full-screen mode or
           alternate-display mode.  Whatever was targeted when ‘q’ or <Esc>
           was pressed will be made current as you return to the top display.
           See topic 5. ALTERNATE-DISPLAY Provisions and the ‘g’ interactive
           command for insight into ‘current’ windows and field groups.
    
           **Note** : Any window that has been scrolled _horizontally_ will be reset
           if any field changes are made via the Fields Management screen.
           Any _vertical_ scrolled position, however, will not be affected.
           See topic 5c. SCROLLING a Window for additional information
           regarding vertical and horizontal scrolling.
    


## 4\. INTERACTIVE Commands



           Listed below is a brief index of commands within categories.  Some
           commands appear more than once  --  their meaning or scope may
           vary depending on the context in which they are issued.
    
             4a. _Global-Commands_
                   <Ent/Sp> ?, =, 0,
                   A, B, d, E, e, g, H, h, I, k, q, r, s, W, X, Y, Z,
                   ^E, ^R
             4b. _Summary-Area-Commands_
                   C, l, t, m, 1, 2, 3, 4, 5, !
             4c. _Task-Area-Commands_
                   Appearance:  b, J, j, x, y, z
                   Content:     c, F, f, O, o, S, U, u, V, v
                   Size:        #, i, n
                   Sorting:     <, >, f, R
             4d. _Bottom-Window-Commands_
                   ^A, ^G, ^K, ^L, ^N, ^P, ^U, Tab, Shift+Tab
             4e. _Color-Mapping_
                   <Ret>, a, B, b, H, M, q, S, T, w, z, @, 0 - 7
             5b. _Commands-for-Windows_
                   -, _, =, +, A, a, G, g, w
             5c. _Scrolling-a-Window_
                   C, Up, Dn, Left, Right, PgUp, PgDn, Home, End
             5d. _Searching-in-a-Window_
                   L, &
             5e. _Filtering-in-a-Window_
                   O, o, ^O, =, +
    
       **4a. GLOBAL Commands**
           The global interactive commands are **always** available in both
           full-screen mode and alternate-display mode.  However, some of
           these interactive commands are **not available** when running in
           Secure mode.
    
           If you wish to know in advance whether or not your top has been
           secured, simply ask for help and view the system summary on the
           second line.
    
             <**Enter** > or <**Space** >  :_Refresh-Display_
                  These commands awaken top and following receipt of any
                  input the entire display will be repainted.  They also
                  force an update of any hotplugged cpu or physical memory
                  changes.
    
                  Use either of these keys if you have a large delay interval
                  and wish to see current status,
    
              **?** | **h** :_Help_
                  There are two help levels available.  The first will
                  provide a reminder of all the basic interactive commands.
                  If top is _secured_ , that screen will be abbreviated.
    
                  Typing ‘h’ or ‘?’ on that help screen will take you to help
                  for those interactive commands applicable to
                  alternate-display mode.
    
              **=** :_Exit-Display-Limits_
                  Removes restrictions on what is shown.  This command will
                  reverse any ‘i’ (idle tasks), ‘n’ (max tasks), ‘v’ (hide
                  children) and ‘F’ focus commands that might be active.  It
                  also provides for an exit from PID monitoring, User
                  filtering, Other filtering, Locate processing and Combine
                  Cpus mode.
    
                  Additionally, if the window has been scrolled it will be
                  reset with this command.
    
              **0** :_Zero-Suppress_ toggle
                  This command determines whether zeros are shown or
                  suppressed for many of the fields in a task window.  Fields
                  like UID, GID, NI, PR or P are not affected by this toggle.
    
              **A** :_Alternate-Display-Mode_ toggle
                  This command will switch between full-screen mode and
                  alternate-display mode.  See topic 5. ALTERNATE-DISPLAY
                  Provisions and the ‘g’ interactive command for insight into
                  ‘current’ windows and field groups.
    
              **B** :_Bold-Disable/Enable_ toggle
                  This command will influence use of the bold terminfo
                  capability and alters **both** the summary area and task area
                  for the ‘current’ window.  While it is intended primarily
                  for use with dumb terminals, it can be applied anytime.
    
                  **Note** : When this toggle is _On_ and top is operating in
                  monochrome mode, the **entire display** will appear as normal
                  text.  Thus, unless the ‘x’ and/or ‘y’ toggles are using
                  reverse for emphasis, there will be no visual confirmation
                  that they are even on.
    
           *  **d** | **s** :_Change-Delay-Time-interval_
                  You will be prompted to enter the delay time, in seconds,
                  between display updates.
    
                  Fractional seconds are honored, but a negative number is
                  not allowed.  Entering 0 causes (nearly) continuous
                  updates, with an unsatisfactory display as the system and
                  tty driver try to keep up with top's demands.  The delay
                  value is inversely proportional to system loading, so set
                  it with care.
    
                  If at any time you wish to know the current delay time,
                  simply ask for help and view the system summary on the
                  second line.
    
              **E** :_Enforce-Summary-Memory-Scale_ in Summary Area
                  With this command you can cycle through the available
                  summary area memory scaling which ranges from KiB
                  (kibibytes or 1,024 bytes) through EiB (exbibytes or
                  1,152,921,504,606,846,976 bytes).
    
                  If you see a ‘+’ between a displayed number and the
                  following label, it means that top was forced to truncate
                  some portion of that number.  By raising the scaling
                  factor, such truncation can be avoided.
    
              **e** :_Enforce-Task-Memory-Scale_ in Task Area
                  With this command you can cycle through the available task
                  area memory scaling which ranges from KiB (kibibytes or
                  1,024 bytes) through PiB (pebibytes or
                  1,125,899,906,842,624 bytes).
    
                  While top will try to honor the selected target range,
                  additional scaling might still be necessary in order to
                  accommodate current values.  If you wish to see a more
                  homogeneous result in the memory columns, raising the
                  scaling range will usually accomplish that goal.  Raising
                  it too high, however, is likely to produce an all zero
                  result which cannot be suppressed with the ‘0’ interactive
                  command.
    
              **g** :_Choose-Another-Window/Field-Group_
                  You will be prompted to enter a number between 1 and 4
                  designating the field group which should be made the
                  ‘current’ window.  You will soon grow comfortable with
                  these 4 windows, especially after experimenting with
                  alternate-display mode.
    
              **H** :_Threads-mode_ toggle
                  When this toggle is _On_ , individual threads will be
                  displayed for all processes in all visible task windows.
                  Otherwise, top displays a summation of all threads in each
                  process.
    
              **I** :_Irix/Solaris-Mode_ toggle
                  When operating in Solaris mode (‘I’ toggled _Off_), a task's
                  cpu usage will be divided by the total number of CPUs.
                  After issuing this command, you'll be told the new state of
                  this toggle.
    
           *  **k** :_Kill-a-task_
                  You will be prompted for a PID and then the signal to send.
    
                  Entering no PID or a negative number will be interpreted as
                  the default shown in the prompt (the first task displayed).
                  A PID value of zero means the top program itself.
    
                  The default signal, as reflected in the prompt, is SIGTERM.
                  However, you can send any signal, via number or name.
    
                  If you wish to abort the kill process, do one of the
                  following depending on your progress:
                      1) at the pid prompt, type an invalid number
                      2) at the signal prompt, type 0 (or any invalid signal)
                      3) at any prompt, type <Esc>
    
              **q** :_Quit_
    
           *  **r** :_Renice-a-Task_
                  You will be prompted for a PID and then the value to nice
                  it to.
    
                  Entering no PID or a negative number will be interpreted as
                  the default shown in the prompt (the first task displayed).
                  A PID value of zero means the top program itself.
    
                  A positive nice value will cause a process to lose
                  priority.  Conversely, a negative nice value will cause a
                  process to be viewed more favorably by the kernel.  As a
                  general rule, ordinary users can only increase the nice
                  value and are prevented from lowering it.
    
                  If you wish to abort the renice process, do one of the
                  following depending on your progress:
                      1) at the pid prompt, type an invalid number
                      2) at the nice prompt, type <Enter> with no input
                      3) at any prompt, type <Esc>
    
              **W** :_Write-the-Configuration-File_
                  This will save all of your options and toggles plus the
                  current display mode and delay time.  By issuing this
                  command just before quitting top, you will be able restart
                  later in exactly that same state.
    
              **X** :_Extra-Fixed-Width_
                  Some fields are fixed width and not scalable.  As such,
                  they are subject to truncation which would be indicated by
                  a ‘+’ in the last position.
    
                  This interactive command can be used to alter the widths of
                  the following fields:
    
                      _field_  _default_    _field_  _default_    _field_   _default_
                      GID       5       Docker    8       WCHAN      10
                      LOGID     5       GROUP     8       nsCGROUP   10
                      RUID      5       LXC       8       nsIPC      10
                      SUID      5       RUSER     8       nsMNT      10
                      UID       5       SUSER     8       nsNET      10
                                        TTY       8       nsPID      10
                                        USER      8       nsTIME     10
                                                          nsUSER     10
                                                          nsUTS      10
    
                  You will be prompted for the amount to be added to the
                  default widths shown above.  Entering zero forces a return
                  to those defaults.
    
                  If you enter a negative number, top will automatically
                  increase the column size as needed until there is no more
                  truncated data.
    
                  **Note** : Whether explicitly or automatically increased, the
                  widths for these fields are never decreased by top.  To
                  narrow them you must specify a smaller number or restore
                  the defaults.
    
              **Y** :_Inspect-Other-Output_
                  After issuing the ‘Y’ interactive command, you will be
                  prompted for a target PID.  Typing a value or accepting the
                  default results in a separate screen.  That screen can be
                  used to view a variety of files or piped command output
                  while the normal top iterative display is paused.
    
                  **Note** : This interactive command is only fully realized when
                  supporting entries have been manually added to the end of
                  the top configuration file.  For details on creating those
                  entries, see topic 6b. ADDING INSPECT Entries.
    
                  Most of the keys used to navigate the Inspect feature are
                  reflected in its header prologue.  There are, however,
                  additional keys available once you have selected a
                  particular file or command.  They are familiar to anyone
                  who has used the pager ‘less’ and are summarized here for
                  future reference.
    
                      _key_      _function_
                      =        alternate status-line, file or pipeline
                      /        find, equivalent to ‘L’ locate
                      n        find next, equivalent to ‘&’ locate next
                      <Space>  scroll down, equivalent to <PgDn>
                      b        scroll up, equivalent to <PgUp>
                      g        first line, equivalent to <Home>
                      G        last line, equivalent to <End>
    
              **Z** :_Change-Color-Mapping_
                  This key will take you to a separate screen where you can
                  change the colors for the ‘current’ window, or for all
                  windows.  For details regarding this interactive command
                  see topic 4e. COLOR Mapping.
    
             **^E** :_Scale-CPU-Time-fields_ (Ctrl key + ‘e’)
                  The ‘time’ fields are normally displayed with the greatest
                  precision their widths permit.  This toggle reduces that
                  precision until it wraps.  It also illustrates the scaling
                  those fields _might_ experience automatically, which usually
                  depends on how long the system runs.
    
                  For example, if ‘MMM:SS.hh’ is shown, each ^E keystroke
                  would change it to: ‘MM:SS’, ‘Hours,MM’, ‘Days+Hours’ and
                  finally ‘Weeks+Days’.
    
                  Not all time fields are subject to the full range of such
                  scaling.
    
           * **^R** :_Renice-an-Autogroup_  (Ctrl key + ‘r’)
                  You will be prompted for a PID and then the value for its
                  autogroup AGNI.
    
                  Entering no PID will be interpreted as the default shown in
                  the prompt (the first task displayed).
    
                  A positive AGNI value will cause processes in that
                  autogroup to lose priority.  Conversely, a negative value
                  causes them to be viewed more favorably by the kernel.
                  Ordinary users are not allowed to set negative AGNI values.
    
                  If you wish to abort the renice process type <Esc>.
    
           *  The commands shown with an asterisk (‘*’) are not available in
              Secure mode, nor will they be shown on the level-1 help screen.
    
       **4b. SUMMARY AREA Commands**
           The summary area interactive commands are **always available** in both
           full-screen mode and alternate-display mode.  They affect the
           beginning lines of your display and will determine the position of
           messages and prompts.
    
           These commands always impact just the ‘current’ window/field
           group.  See topic 5. ALTERNATE-DISPLAY Provisions and the ‘g’
           interactive command for insight into ‘current’ windows and field
           groups.
    
              **C** :_Show-scroll-coordinates_ toggle
                  Toggle an informational message which is displayed whenever
                  the message line is not otherwise being used.  For
                  additional information see topic 5c. SCROLLING a Window.
    
              **l** :_Load-Average/Uptime_ toggle
                  This is also the line containing the program name (possibly
                  an alias) when operating in full-screen mode or the
                  ‘current’ window name when operating in alternate-display
                  mode.
    
              **t** :_Task/Cpu-States_ toggle
                  This command affects from 2 to many summary area lines,
                  depending on the state of the ‘1’, ‘2’ or ‘3’ command
                  toggles and whether or not top is running under true SMP.
    
                  This portion of the summary area is also influenced by the
                  ‘H’ interactive command toggle, as reflected in the total
                  label which shows either Tasks or Threads.
    
                  This command serves as a 4-way toggle, cycling through
                  these modes:
                      1. detailed percentages by category
                      2. abbreviated user/system and total % + bar graph
                      3. abbreviated user/system and total % + block graph
                      4. turn off task and cpu states display
    
                  When operating in either of the graphic modes, the display
                  becomes much more meaningful when individual CPUs or NUMA
                  nodes are also displayed.  See the the ‘1’, ‘2’ and ‘3’
                  commands below for additional information.
    
              **m** :_Memory/Swap-Usage_ toggle
                  This command affects the two summary area lines dealing
                  with physical and virtual memory.
    
                  This command serves as a 4-way toggle, cycling through
                  these modes:
                      1. detailed percentages by memory type
                      2. abbreviated % used/total available + bar graph
                      3. abbreviated % used/total available + block graph
                      4. turn off memory display
    
              **1** :_Single/Separate-Cpu-States_ toggle
                  This command affects how the ‘t’ command's Cpu States
                  portion is shown.  Although this toggle exists primarily to
                  serve massively-parallel SMP machines, it is not restricted
                  to solely SMP environments.
    
                  When you see ‘%Cpu(s):’ in the summary area, the ‘1’ toggle
                  is _On_ and all cpu information is gathered in a single line.
                  Otherwise, each cpu is displayed separately as: ‘%Cpu0,
                  %Cpu1, ...’ up to available screen height.
    
              **2** :_NUMA-Nodes/Cpu-Summary_ toggle
                  This command toggles between the ‘1’ command cpu summary
                  display (only) or a summary display plus the cpu usage
                  statistics for each NUMA Node.  It is only available if a
                  system has the requisite NUMA support.
    
              **3** :_Expand-NUMA-Node_
                  You will be invited to enter a number representing a NUMA
                  Node.  Thereafter, a node summary plus the statistics for
                  each cpu in that node will be shown until the ‘1’, ‘2’ or
                  ‘4’ command toggle is pressed.  This interactive command is
                  only available if a system has the requisite NUMA support.
    
              **4** :_Display-Multiple-Elements-Adjacent_ toggle
                  This command toggle turns the ‘1’ toggle _Off_ and shows
                  multiple CPU and Memory results on each line.  Each
                  successive ‘4’ key adds another CPU until again reverting
                  to separate lines for CPU and Memory results.
    
                  A maximum of 8 CPUs per line can be displayed in this
                  manner.  However, data truncation may occur before reaching
                  the maximum.  That is definitely true when displaying
                  detailed statistics via the ‘t’ command toggle since such
                  data cannot be scaled like the graphic representations.
    
                  If one wished to quickly exit adjacent mode without cycling
                  all the way to 8, simply use the ‘1’ command toggle.
    
              **5** :_Display-P-Cores-and-E-Cores_ toggle
                  This command toggle is only active when the ‘t’ toggle is
                  _On_ and the ‘1’, ‘2’, ‘3’ and ‘!’ toggles are _Off_ , thus
                  showing individual CPU results.  It assumes a platform has
                  multiple cores of two distinct types, either multi-threaded
                  (P-Core) or single-threaded (E-Core).
    
                  While normally each cpu is displayed as ‘%Cpu0, %Cpu1,
                  ...’, this toggle can be used to identify and/or filter
                  those cpus by their core type, either P-Core (performance)
                  or E-Core (efficient).
    
                  The 1st time ‘5’ is struck, each CPU is displayed as ‘%Cp**P** ’
                  or ‘%Cp**E** ’ representing the two core types.  The 2nd time,
                  only P-Cores (%Cp**P**) will be shown.  The 3rd time, only E-
                  Cores (%Cp**E**) are displayed.  When this command toggle is
                  struck for the 4th time, the CPU display returns to the
                  normal ‘%Cpu’ convention.
    
                  If separate _performance_ and _efficient_ categories are not
                  present, this command toggle will have no effect.
    
              **!** :_Combine-Cpus-Mode_ toggle
                  This command toggle is intended for massively parallel SMP
                  environments where, even with the ‘4’ command toggle, not
                  all processors can be displayed.  With each press of ‘!’
                  the number of cpus combined is doubled thus reducing the
                  total number of cpu lines displayed.
    
                  For example, with the first press of ‘!’ two cpus will be
                  combined and displayed as ‘0-1, 2-3, ...’ instead of the
                  normal ‘%Cpu0, %Cpu1, %Cpu2, %Cpu3, ...’.  With a second
                  ‘!’ command toggle four cpus are combined and shown as
                  ‘0-3, 4-7, ...’.  Then the third ‘!’ press, combining eight
                  cpus, shows as ‘0-7, 8-15, ...’, etc.
    
                  Such progression continues until individual cpus are again
                  displayed and impacts both the ‘1’ and ‘4’ toggles (one or
                  multiple columns).  Use the ‘=’ command to exit **Combine**
                  **Cpus** mode.
    
           **Note** : If the entire summary area has been toggled _Off_ for any
           window, you would be left with just the **message line**.  In that
           way, you will have maximized available task rows but (temporarily)
           sacrificed the program name in full-screen mode or the ‘current’
           window name when in alternate-display mode.
    
       **4c. TASK AREA Commands**
           The task area interactive commands are **always** available in
           full-screen mode.
    
           The task area interactive commands are **never available** in
           alternate-display mode _if_ the ‘current’ window's task display has
           been toggled _Off_ (see topic 5. ALTERNATE-DISPLAY Provisions).
    
           **APPEARANCE** of task window
    
              **J** :_Justify-Numeric-Columns_ toggle
                  Alternates between right-justified (the default) and left-
                  justified numeric data.  If the numeric data completely
                  fills the available column, this command toggle may impact
                  the column header only.
    
              **j** :_Justify-Character-Columns_ toggle
                  Alternates between left-justified (the default) and right-
                  justified character data.  If the character data completely
                  fills the available column, this command toggle may impact
                  the column header only.
    
             The following commands will also be influenced by the state of
             the global ‘B’ (bold enable) toggle.
    
              **b** :_Bold/Reverse_ toggle
                  This command will impact how the ‘x’ and ‘y’ toggles are
                  displayed.  It may also impact the summary area when a bar
                  graph has been selected for cpu states or memory usage via
                  the ‘t’ or ‘m’ toggles.
    
              **x** :_Column-Highlight_ toggle
                  Changes highlighting for the current sort field.  If you
                  forget which field is being sorted this command can serve
                  as a quick visual reminder, providing the sort field is
                  being displayed.  The sort field might _not_ be visible
                  because:
                      1) there is insufficient _Screen Width_
                      2) the ‘f’ interactive command turned it _Off_
    
              **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** :_Maintain-Parent-Focus_ toggle
                  When in forest view mode, this key serves as a toggle to
                  retain focus on a target task, presumably one with forked
                  children.  If forest view mode is _Off_ this key has no
                  effect.
    
                  The toggle is applied to the first (topmost) process in the
                  ‘current’ window.  Once established, that task is always
                  displayed as the first (topmost) process along with its
                  forked children.  All other processes will be suppressed.
    
                  **Note** : keys like ‘i’ (idle tasks), ‘n’ (max tasks), ‘v’
                  (hide children) and User/Other filtering remain accessible
                  and can impact what is displayed.
    
              **f** :_Fields-Management_
                  This key displays a separate screen where you can change
                  which fields are displayed, their order and also designate
                  the sort field.  For additional information on this
                  interactive command see topic 3b. MANAGING Fields.
    
              **O** | **o** :_Other-Filtering_
                  You will be prompted for the selection criteria which then
                  determines which tasks will be shown in the ‘current’
                  window.  Your criteria can be made case sensitive or case
                  can be ignored.  And you determine if top should include or
                  exclude matching tasks.
    
                  See topic 5e. FILTERING in a window for details on these
                  and additional related interactive commands.
    
              **S** :_Cumulative-Time-Mode_ toggle
                  When Cumulative mode is _On_ , each process is listed with the
                  cpu time that it and its dead children have used.
    
                  When _Off_ , programs that fork into many separate tasks will
                  appear less demanding.  For programs like ‘init’ or a shell
                  this is appropriate but for others, like compilers, perhaps
                  not.  Experiment with two task windows sharing the same
                  sort field but with different ‘S’ states and see which
                  representation you prefer.
    
                  After issuing this command, you'll be informed of the new
                  state of this toggle.  If you wish to know in advance
                  whether or not Cumulative mode is in effect, simply ask for
                  help and view the window summary on the second line.
    
              **U** | **u** :_Show-Specific-User-Only_
                  You will be prompted for the **uid** or **name** of the user to
                  display.  The -u option matches on  **effective** user whereas
                  the -U option matches on **any** user (real, effective, saved,
                  or filesystem).
    
                  Thereafter, in that task window only matching users will be
                  shown, or possibly no processes will be shown.  Prepending
                  an exclamation point (‘!’) to the user id or name instructs
                  top to display only processes with users not matching the
                  one provided.
    
                  Different task windows can be used to filter different
                  users.  Later, if you wish to monitor all users again in
                  the ‘current’ window, re-issue this command but just press
                  <Enter> at the prompt.
    
              **V** :_Forest-View-Mode_ toggle
                  In this mode, processes are reordered according to their
                  parents and the layout of the COMMAND column resembles that
                  of a tree.  In forest view mode it is still possible to
                  toggle between program name and command line (see the ‘c’
                  interactive command) or between processes and threads (see
                  the ‘H’ interactive command).
    
                  **Note** : Typing any key affecting the sort order will exit
                  forest view mode in the ‘current’ window.  See topic 4c.
                  TASK AREA Commands, SORTING for information on those keys.
    
              **v** :_Hide/Show-Children_ toggle
                  When in forest view mode, this key serves as a toggle to
                  collapse or expand the children of a parent.
    
                  The toggle is applied against the first (topmost) process
                  in the ‘current’ window.  See topic 5c. SCROLLING a Window
                  for additional information regarding vertical scrolling.
    
                  If the target process has not forked any children, this key
                  has no effect.  It also has no effect when not in forest
                  view mode.
    
           **SIZE** of task window
    
              **i** :_Idle-Process_ toggle
                  Displays all tasks or just active tasks.  When this toggle
                  is _Off_ , tasks that have not used any CPU since the last
                  update will not be displayed.  However, due to the
                  granularity of the %CPU and TIME+ fields, some processes
                  may still be displayed that _appear_ to have used _no_ CPU.
    
                  If this command is applied to the last task display when in
                  alternate-display mode, then it will not affect the
                  window's size, as all prior task displays will have already
                  been painted.
    
              **n** | **#** :_Set-Maximum-Tasks_
                  You will be prompted to enter the number of tasks to
                  display.  The lessor of your number and available screen
                  rows will be used.
    
                  When used in alternate-display mode, this is the command
                  that gives you precise control over the size of each
                  currently visible task display, except for the very last.
                  It will not affect the last window's size, as all prior
                  task displays will have already been painted.
    
                  **Note** : If you wish to increase the size of the last visible
                  task display when in alternate-display mode, simply
                  decrease the size of the task display(s) above it.
    
           **SORTING** of task window
    
              For compatibility, this top supports most of the former top
              sort keys.  Since this is primarily a service to former top
              users, these commands do not appear on any help screen.
                    _command_   _sorted-field_                  _supported_
                    A         start time (non-display)      **No**
                    M         %MEM                          Yes
                    N         PID                           Yes
                    P         %CPU                          Yes
                    T         TIME+                         Yes
    
              Before using any of the following sort provisions, top suggests
              that you temporarily turn on column highlighting using the ‘x’
              interactive command.  That will help ensure that the actual
              sort environment matches your intent.
    
              The following interactive commands will **only** be honored when
              the current sort field is **visible**.  The sort field might _not_ be
              visible because:
                    1) there is insufficient _Screen Width_
                    2) the ‘f’ interactive command turned it _Off_
    
                 **<  **:_Move-Sort-Field-Left_
                     Moves the sort column to the left unless the current
                     sort field is the first field being displayed.
    
                 **>  **:_Move-Sort-Field-Right_
                     Moves the sort column to the right unless the current
                     sort field is the last field being displayed.
    
              The following interactive commands will **always** be honored
              whether or not the current sort field is visible.
    
                 **f** :_Fields-Management_
                     This key displays a separate screen where you can change
                     which field is used as the sort column, among other
                     functions.  This can be a convenient way to simply
                     verify the current sort field, when running top with
                     column highlighting turned _Off_.
    
                 **R** :_Reverse/Normal-Sort-Field_ toggle
                     Using this interactive command you can alternate between
                     high-to-low and low-to-high sorts.
    
       **4d. BOTTOM WINDOW Commands**
           These keys invoke a separate window at the bottom of the screen
           while normal top monitoring continues uninterrupted.  Keying the
           _same_ ‘Ctrl’ command a second time removes that separate window as
           does the ‘=’ command.
    
              **^A** :_Display-Capabilities_          (Ctrl key + ‘a’)
              **^G** :_Display-Control-Groups_        (Ctrl key + ‘g’)
              **^K** :_Display-Cmdline_               (Ctrl key + ‘k’)
              **^L** :_Display-Logged-Messages_       (Ctrl key + ‘l’)
              **^N** :_Display-Environment_           (Ctrl key + ‘n’)
              **^P** :_Display-Namesspaces_           (Ctrl key + ‘p’)
              **^U** :_Display-Supplementary-Groups_  (Ctrl key + ‘u’)
    
           Except for the Ctrl+L command, all the above keys are applied to
           the first process displayed and will show that task's full
           (potentially wrapped) information.  Thus, the Up/Down arrow keys
           or their aliases will be important.
    
           The **Tab** key or **Shift+Tab** combination can be used to highlight
           individual elements being displayed in the bottom window.
    
           Notable among these provisions is the Ctrl+N (environment)
           command.  Its output can be extensive and not easily read when
           line wrapped.  A more readable version can be achieved with an
           ‘Inspect’ entry in the rcfile like the following.
    
               pipe ^I Environment ^I cat /proc/%d/environ | tr '\0' '\n'
    
           See the ‘Y’ interactive command under 4a. GLOBAL Commands and
           topic 6b. ADDING INSPECT Entries for additional information.
    
           Unlike the other commands, **Ctrl+L**(logged messages) is not
           associated with a specific task.  Rather, up to 10 of the most
           recent messages issued by top are recalled for review.
    
       **4e. 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.
               **5** upper case letters to select a **target**
               **8** numbers to select a **color**(@ selects no color)
               normal toggles available
                   B         :bold disable/enable
                   b         :running tasks "bold"/reverse
                   z         :color/mono
               other commands available
                   a/w       :apply, then go to next/prior
                   <Enter>   :apply and exit
                   q         :abandon current changes and exit
    
           If you use ‘a’ or ‘w’ to cycle the targeted window, you will have
           applied the color scheme that was displayed when you left that
           window.  You can, of course, easily return to any window and
           reapply different colors or turn colors _Off_ completely with the
           ‘z’ toggle.
    
           The Color Mapping screen can also be used to change the ‘current’
           window/field group in either full-screen mode or alternate-display
           mode.  Whatever was targeted when ‘q’ or <Enter> was pressed will
           be made current as you return to the top display.
    


## 5\. ALTERNATE-DISPLAY Provisions



       **5a. WINDOWS Overview**
           **Field Groups/Windows** :
              In full-screen mode there is a single window represented by the
              entire screen.  That single window can still be changed to
              display 1 of 4 different **field groups**(see the ‘g’ interactive
              command, repeated below).  Each of the 4 field groups has a
              unique separately configurable **summary area** and its own
              configurable **task area**.
    
              In alternate-display mode, those 4 underlying field groups can
              now be made visible simultaneously, or can be turned _Off_
              individually at your command.
    
              The summary area will always exist, even if it's only the
              message line.  At any given time only _one_ summary area can be
              displayed.  However, depending on your commands, there could be
              from _zero_ to _four_ separate task displays currently showing on
              the screen.
    
           **Current Window** :
              The ‘current’ window is the window associated with the summary
              area and the window to which task related commands are always
              directed.  Since in alternate-display mode you can toggle the
              task display _Off_ , some commands might be restricted for the
              ‘current’ window.
    
              A further complication arises when you have toggled the first
              summary area line _Off_.  With the loss of the window name (the
              ‘l’ toggled line), you'll not easily know what window is the
              ‘current’ window.
    
       **5b. COMMANDS for Windows**
              **-** | **_** :_Show/Hide-Window(s)_ toggles
                  The ‘-’ key turns the ‘current’ window's task display _On_
                  and _Off_.  When _On_ , that task area will show a minimum of
                  the columns header you've established with the ‘f’
                  interactive command.  It will also reflect any other task
                  area options/toggles you've applied yielding zero or more
                  tasks.
    
                  The ‘_’ key does the same for all task displays.  In other
                  words, it switches between the currently visible task
                  display(s) and any task display(s) you had toggled _Off_.  If
                  all 4 task displays are currently visible, this interactive
                  command will leave the summary area as the only display
                  element.
    
           *  **=** | **+** :_Equalize/Reset-Window(s)_
                  The ‘=’ key forces the ‘current’ window's task display to
                  be visible.  It also reverses any active ‘i’ (idle tasks),
                  ‘n’ (max tasks), ‘u/U’ (user filter), ‘o/O’ (other filter),
                  ‘v’ (hide children), ‘F’ focused, ‘L’ (locate) and ‘!’
                  (combine cpus) commands.  Also, if the window had been
                  scrolled, it will be reset with this command.  See topic
                  5c. SCROLLING a Window for additional information regarding
                  vertical and horizontal scrolling.
    
                  The ‘+’ key does the same for all windows.  The four task
                  displays will reappear, evenly balanced, while retaining
                  any customizations previously applied beyond those noted
                  for the ‘=’ command toggle.
    
           *  **A** :_Alternate-Display-Mode_ toggle
                  This command will switch between full-screen mode and
                  alternate-display mode.
    
                  The first time you issue this command, all four task
                  displays will be shown.  Thereafter when you switch modes,
                  you will see only the task display(s) you've chosen to make
                  visible.
    
           *  **a** | **w** :_Next-Window-Forward/Backward_
                  This will change the ‘current’ window, which in turn
                  changes the window to which commands are directed.  These
                  keys act in a circular fashion so you can reach any desired
                  window using either key.
    
                  Assuming the window name is visible (you have not toggled
                  ‘l’ _Off_), whenever the ‘current’ window name loses its
                  emphasis/color, that's a reminder the task display is _Off_
                  and many commands will be restricted.
    
              **G** :_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
    
           *  **g** :_Choose-Another-Window/Field-Group_
                  You will be prompted to enter a number between 1 and 4
                  designating the field group which should be made the
                  ‘current’ window.
    
                  In full-screen mode, this command is necessary to alter the
                  ‘current’ window.  In alternate-display mode, it is simply
                  a less convenient alternative to the ‘a’ and ‘w’ commands.
    
       **5c. SCROLLING a Window**
           Typically a task window is a partial view into a system's total
           tasks/threads which shows only some of the available
           fields/columns.  With these scrolling keys, you can move that view
           vertically or horizontally to reveal any desired task or column.
    
           **Up** ,**PgUp** :_Scroll-Tasks_
               Move the view up toward the first task row, until the first
               task is displayed at the top of the ‘current’ window.  The _Up_
               arrow key moves a single line while _PgUp_ scrolls the entire
               window.
    
           **Down** ,**PgDn** :_Scroll-Tasks_
               Move the view down toward the last task row, until the last
               task is the only task displayed at the top of the ‘current’
               window.  The _Down_ arrow key moves a single line while _PgDn_
               scrolls the entire window.
    
           **Left** ,**Right** :_Scroll-Columns_
               Move the view of displayable fields horizontally one column at
               a time.
    
               **Note** : As a reminder, some fields/columns are not fixed-width
               but allocated all remaining screen width when visible.  When
               scrolling right or left, that feature may produce some
               unexpected results initially.
    
               Additionally, there are special provisions for any variable
               width field when positioned as the last displayed field.  Once
               that field is reached via the right arrow key, and is thus the
               only column shown, you can continue scrolling horizontally
               within such a field.  See the ‘C’ interactive command below
               for additional information.
    
           **Home** :_Jump-to-Home-Position_
               Reposition the display to the un-scrolled coordinates.
    
           **End** :_Jump-to-End-Position_
               Reposition the display so that the rightmost column reflects
               the last displayable field and the bottom task row represents
               the last task.
    
               **Note** : From this position it is still possible to scroll _down_
               and _right_ using the arrow keys.  This is true until a single
               column and a single task is left as the only display element.
    
           **C** :_Show-scroll-coordinates_ toggle
               Toggle an informational message which is displayed whenever
               the message line is not otherwise being used.  That message
               will take one of two forms depending on whether or not a
               variable width column has also been scrolled.
    
                 **scroll coordinates: y = n/n (tasks), x = n/n (fields)**
                 scroll coordinates: y = n/n (tasks), x = n/n (fields) **+ nn**
    
               The coordinates shown as **n** /**n** are relative to the upper left
               corner of the ‘current’ window.  The additional ‘**+ nn** ’
               represents the displacement into a variable width column when
               it has been scrolled horizontally.  Such displacement occurs
               in normal 8 character tab stop amounts via the right and left
               arrow keys.
    
               **y = n/n (tasks)**
                   The first **n** represents the topmost visible task and is
                   controlled by scrolling keys.  The second **n** is updated
                   automatically to reflect total tasks.
    
               **x = n/n (fields)**
                   The first **n** represents the leftmost displayed column and
                   is controlled by scrolling keys.  The second **n** is the
                   total number of displayable fields and is established with
                   the ‘**f** ’ interactive command.
    
           The above interactive commands are **always** available in full-screen
           mode but **never** available in alternate-display mode if the
           ‘current’ window's task display has been toggled _Off_.
    
           **Note** : When any form of filtering is active, you can expect some
           slight aberrations when scrolling since not all tasks will be
           visible.  This is particularly apparent when using the Up/Down
           arrow keys.
    
       **5d. SEARCHING in a Window**
           You can use these interactive commands to locate a task row
           containing a particular value.
    
           **L** :_Locate-a-string_
               You will be prompted for the case-sensitive string to locate
               starting from the current window coordinates.  There are no
               restrictions on search string content.
    
               Searches are not limited to values from a single field or
               column.  All of the values displayed in a task row are allowed
               in a search string.  You may include spaces, numbers, symbols
               and even forest view artwork.
    
               Keying <Enter> with no input will effectively disable the ‘&’
               key until a new search string is entered.
    
           **&  **:_Locate-next_
               Assuming a search string has been established, top will
               attempt to locate the next occurrence.
    
           When a match is found, the current window is repositioned
           vertically so the task row containing that string is first.  The
           scroll coordinates message can provide confirmation of such
           vertical repositioning (see the ‘C’ interactive command).
           Horizontal scrolling, however, is never altered via searching.
    
           The availability of a matching string will be influenced by the
           following factors.
    
              a. Which fields are displayable from the total available,
                 see topic 3b. MANAGING Fields.
    
              b. Scrolling a window vertically and/or horizontally,
                 see topic 5c. SCROLLING a Window.
    
              c. The state of the command/command-line toggle,
                 see the ‘c’ interactive command.
    
              d. The stability of the chosen sort column,
                 for example PID is good but %CPU bad.
    
           If a search fails, restoring the ‘current’ window home
           (unscrolled) position, scrolling horizontally, displaying command-
           lines or choosing a more stable sort field could yet produce a
           successful ‘&’ search.
    
           The above interactive commands are **always** available in full-screen
           mode but **never** available in alternate-display mode if the
           ‘current’ window's task display has been toggled _Off_.
    
       **5e. FILTERING in a Window**
           You can use this ‘Other Filter’ feature to establish selection
           criteria which will then determine which tasks are shown in the
           ‘current’ window.  Such filters can be made persistent if
           preserved in the rcfile via the ‘W’ interactive command.
    
           Establishing a filter requires: 1) a field name; 2) an operator;
           and 3) a selection value, as a minimum.  This is the most complex
           of top's user input requirements so, when you make a mistake,
           command recall will be your friend.  Remember the Up/Down arrow
           keys or their aliases when prompted for input.
    
           **Filter Basics**
    
              1. field names are case sensitive and spelled as in the header
    
              2. selection values need not comprise the full displayed field
    
              3. a selection is either case insensitive or sensitive to case
    
              4. the default is inclusion, prepending ‘!’ denotes exclusions
    
              5. multiple selection criteria can be applied to a task window
    
              6. inclusion and exclusion criteria can be used simultaneously
    
              7. the 1 equality and 2 relational filters can be freely mixed
    
              8. separate unique filters are maintained for each task window
    
              If a field is not turned on or is not currently in view, then
              your selection criteria will not affect the display.  Later,
              should a filtered field become visible, the selection criteria
              will then be applied.
    
           **Keyboard Summary**
    
             **O** :_Other-Filter_ (upper case)
                 You will be prompted to establish a **case sensitive** filter.
    
             **o** :_Other-Filter_ (lower case)
                 You will be prompted to establish a filter that **ignores case**
                 when matching.
    
            **^O** :_Show-Active-Filters_ (Ctrl key + ‘o’)
                 This can serve as a reminder of which filters are active in
                 the ‘current’ window.  A summary will be shown on the
                 message line until you press the <Enter> key.
    
             **=** :_Reset-Filtering_ in current window
                 This clears all of your selection criteria in the ‘current’
                 window.  It also has additional impact so please see topic
                 4a. GLOBAL Commands.
    
             **+** :_Reset-Filtering_ in all windows
                 This clears the selection criteria in all windows, assuming
                 you are in alternate-display mode.  As with the ‘=’
                 interactive command, it too has additional consequences so
                 you might wish to see topic 5b.  COMMANDS for Windows.
    
           **Input Requirements**
    
              When prompted for selection criteria, the data you provide must
              take one of two forms.  There are 3 required pieces of
              information, with a 4th as optional.  These examples use spaces
              for clarity but your input generally would not.
                      #1           **#2** #3              ( required )
                      Field-Name   ?   include-if-value
                   **!** Field-Name   ?   **exclude** -if-value
                   #4                                  ( optional )
    
              Items #1, #3 and #4 should be self-explanatory.  Item **#2**
              represents both a required _delimiter_ and the _operator_ which
              must be one of either equality (‘=’) or relation (‘<’ or ‘>’).
    
              The ‘=’ equality operator requires only a partial match and
              that can reduce your ‘if-value’ input requirements.  The ‘>’ or
              ‘<’ relational operators always employ string comparisons, even
              with numeric fields.  They are designed to work with a field's
              default _justification_ and with homogeneous data.  When some
              field's numeric amounts have been subjected to _scaling_ while
              others have not, that data is no longer homogeneous.
    
              If you establish a relational filter and you **have** changed the
              default Numeric or Character _justification_ , that filter is
              likely to fail.  When a relational filter is applied to a
              memory field and you **have not** changed the _scaling_ , it may
              produce misleading results.  This happens, for example, because
              ‘100.0m’ (MiB) would appear greater than ‘1.000g’ (GiB) when
              compared as strings.
    
              If your filtered results appear suspect, simply altering
              justification or scaling may yet achieve the desired objective.
              See the ‘j’, ‘J’ and ‘e’ interactive commands for additional
              information.
    
           **Potential Problems**
    
              These **GROUP** filters could produce the exact same results or the
              second one might not display anything at all, just a blank task
              window.
                   GROUP=root        ( only the same results when )
                   GROUP=ROOT        ( invoked via lower case ‘o’ )
    
              Either of these **RES** filters might yield inconsistent and/or
              misleading results, depending on the current memory scaling
              factor.  Or both filters could produce the exact same results.
                   RES>9999          ( only the same results when )
                   !RES<10000        ( memory scaling is at ‘KiB’ )
    
              This **nMin** filter illustrates a problem unique to scalable
              fields.  This particular field can display a maximum of 4
              digits, beyond which values are automatically scaled to KiB or
              above.  So while amounts greater than 9999 exist, they will
              appear as 2.6m, 197k, etc.
                   nMin>9999         ( always a blank task window )
    
           **Potential Solutions**
    
              These examples illustrate how Other Filtering can be creatively
              applied to achieve almost any desired result.  Single quotes
              are sometimes shown to delimit the spaces which are part of a
              filter or to represent a request for status (^O) accurately.
              But if you used them with if-values in real life, no matches
              would be found.
    
              Assuming field **nTH** is displayed, the first filter will result
              in only multi-threaded processes being shown.  It also reminds
              us that a trailing space is part of every displayed field.  The
              second filter achieves the exact same results with less typing.
                   !nTH=‘ 1 ’                ( ‘’ for clarity only )
                   nTH>1                     ( same with less i/p )
    
              With Forest View mode active and the **COMMAND** column in view,
              this filter effectively collapses child processes so that just
              3 levels are shown.
                   !COMMAND=‘       ‘- ’   ( ‘’ for clarity only )
    
              The final two filters appear as in response to the status
              request key (^O).  In reality, each filter would have required
              separate input.  The **PR** example shows the two concurrent
              filters necessary to display tasks with priorities of 20 or
              more, since some might be negative.  Then by exploiting
              trailing spaces, the **nMin** series of filters could achieve the
              failed ‘9999’ objective discussed above.
                   ‘PR>20’ + ‘!PR=-’         ( 2 for right result )
                   ‘!nMin=0 ’ + ‘!nMin=1 ’ + ‘!nMin=2 ’ + ‘!nMin=3 ’ ...
    


## 6\. FILES



       **6a. PERSONAL Configuration File**
           This file is created or updated via the ‘W’ interactive command.
    
           The legacy version is written as ‘$HOME/.your-name-4-top’ + ‘rc’
           with a leading period.
    
           A newly created configuration file is written as
           ‘procps/your-name-4-top’ + ‘rc’ without a leading period.  The
           procps directory will be subordinate to either $XDG_CONFIG_HOME
           when set as an absolute path or the $HOME/.config directory.
    
           While not intended to be edited manually, here is the general
           layout:
               global   # line  1: the program name/alias notation
                 "      # line  2: id,altscr,irixps,delay,curwin
               per ea   # line  a: winname,fieldscur
               window   # line  b: winflags,sortindx,maxtasks,etc
                 "      # line  c: summclr,msgsclr,headclr,taskclr
               global   # line 15: additional miscellaneous settings
                 "      # any remaining lines are devoted to optional
                 "      # active ‘other filters’ discussed in section 5e above
                 "      # plus ‘inspect’ entries discussed in section 6b below
    
           If a valid absolute path to the rcfile cannot be established,
           customizations made to a running top will be impossible to
           preserve.
    
       **6b. ADDING INSPECT Entries**
           To exploit the ‘Y’ interactive command, you must add entries at
           the **end** of the top personal configuration file.  Such entries
           simply reflect a file to be read or command/pipeline to be
           executed whose results will then be displayed in a separate
           scrollable, searchable window.
    
           If you don't know the location or name of your top rcfile, use the
           ‘W’ interactive command to rewrite it and note those details.
    
           Inspect entries can be added with a redirected echo or by editing
           the configuration file.  Redirecting an echo risks overwriting the
           rcfile should it replace (>) rather than append (>>) to that file.
           Conversely, when using an editor care must be taken not to corrupt
           existing lines, some of which could contain unprintable data or
           unusual characters depending on the top version under which that
           configuration file was saved.
    
           Those Inspect entries beginning with a ‘#’ character are ignored,
           regardless of content.  Otherwise they consist of the following 3
           elements, each of which _must_ be separated by a tab character (thus
           2 ‘\t’ total):
    
             .type:  literal ‘file’ or ‘pipe’
             .name:  selection shown on the Inspect screen
             .fmts:  string representing a path or command
    
           The two types of Inspect entries are _not_ interchangeable.  Those
           designated ‘**file** ’ will be accessed using fopen and must reference
           a single file in the ‘.fmts’ element.  Entries specifying ‘**pipe** ’
           will employ popen, their ‘.fmts’ element could contain many
           pipelined commands and, none can be interactive.
    
           If the file or pipeline represented in your ‘.fmts’ deals with the
           specific PID input or accepted when prompted, then the format
           string must also contain the ‘**%d** ’ specifier, as these examples
           illustrate.
    
             .fmts=  /proc/_%d_ /numa_maps
             .fmts=  lsof -P -p _%d_
    
           For ‘**pipe** ’ type entries only, you may also wish to redirect stderr
           to stdout for a more comprehensive result.  Thus the format string
           becomes:
    
             .fmts=  pmap -x %d _2 >&1_
    
           Here are examples of both types of Inspect entries as they might
           appear in the rcfile.  The first entry will be ignored due to the
           initial ‘#’ character.  For clarity, the pseudo tab depictions
           (^I) are surrounded by an extra space but the actual tabs would
           not be.
    
             # pipe ^I Sockets ^I lsof -n -P -i 2>&1
             pipe ^I Open Files ^I lsof -P -p %d 2>&1
             file ^I NUMA Info ^I /proc/%d/numa_maps
             pipe ^I Log ^I tail -n100 /var/log/syslog | sort -Mr
    
           Except for the commented entry above, these next examples show
           what could be echoed to achieve similar results, assuming the
           rcfile name was ‘.toprc’.  However, due to the embedded tab
           characters, each of these lines should be preceded by ‘**/bin/echo**
           **-e** ’, not just a simple an ‘echo’, to enable backslash
           interpretation regardless of which shell you use.
    
             "pipe\tOpen Files\tlsof -P -p %d 2>&1" >> ~/.toprc
             "file\tNUMA Info\t/proc/%d/numa_maps" >> ~/.toprc
             "pipe\tLog\ttail -n200 /var/log/syslog | sort -Mr" >> ~/.toprc
    
           If any inspect entry you create produces output with unprintable
           characters they will be displayed in either the ^C notation or
           hexadecimal <FF> form, depending on their value.  This applies to
           tab characters as well, which will show as ‘^I’.  If you want a
           truer representation, any embedded tabs should be expanded.  The
           following example takes what could have been a ‘file’ entry but
           employs a ‘pipe’ instead so as to expand the embedded tabs.
    
             # next would have contained ‘\t’ ...
             # file ^I <your_name> ^I /proc/%d/status
             # but this will eliminate embedded ‘\t’ ...
             pipe ^I <your_name> ^I cat /proc/%d/status | expand -
    
           **Note** : Some programs might rely on _SIGINT_ to end.  Therefore, if a
           ‘**pipe** ’ such as the following is established, one must use Ctrl-C
           to terminate it in order to review the results.  This is the
           single occasion where a ‘^C’ will not also terminate top.
    
             pipe ^I Trace ^I /usr/bin/strace -p %d 2>&1
    
           Lastly, while ‘**pipe** ’ type entries have been discussed in terms of
           pipelines and commands, there is nothing to prevent you from
           including  _shell scripts_ as well.  Perhaps even newly created
           scripts designed specifically for the ‘Y’ interactive command.
    
           For example, as the number of your Inspect entries grows over
           time, the ‘Options:’ row will be truncated when screen width is
           exceeded.  That does not affect operation other than to make some
           selections invisible.  However, if some choices are lost to
           truncation but you want to see more options, there is an easy
           solution hinted at below.
    
             Inspection Pause at pid ...
             Use:  left/right then <Enter> ...
             Options:  help  1  2  3  4  5  6  7  8  9  10  11 ...
    
           The entries in the top rcfile would have a number for the ‘.name’
           element and the ‘help’ entry would identify a shell script you've
           written explaining what those numbered selections actually mean.
           In that way, many more choices can be made visible.
    
       **6c. SYSTEM Configuration File**
           This configuration file represents defaults for users who have not
           saved their own configuration file.  The format mirrors exactly
           the personal configuration file and can also include ‘inspect’
           entries as explained above.
    
           Creating it is a simple process.
    
           1. Configure top appropriately for your installation and preserve
           that configuration with the ‘W’ interactive command.
    
           2. Add and test any desired ‘inspect’ entries.
    
           3. Copy that configuration file to the _/etc/_ directory as
           ‘**topdefaultrc** ’.
    
       **6d. SYSTEM Restrictions File**
           The presence of this file will influence which version of the help
           screen is shown to an ordinary user.
    
           More importantly, it will limit what ordinary users are allowed to
           do when top is running.  They will not be able to issue the
           following commands.
               k        Kill a task
               r        Renice a task
               d or s   Change delay/sleep interval
    
           This configuration file is not created by top.  Rather, it is
           created manually and placed it in the _/etc/_ directory as ‘**toprc** ’.
    
           It should have exactly two lines, as shown in this example:
               s        # line 1: secure mode switch
               5.0      # line 2: delay interval in seconds
    


## 7\. ENVIRONMENT VARIABLE(S)



           The value set for the following is unimportant, just its presence.
    
           LIBPROC_HIDE_KERNEL
                  This will prevent display of any kernel threads and exclude
                  such processes from the summary area Tasks/Threads counts.
    


## 8\. 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.
    
       **8a. Kernel Magic**
           For these stupid tricks, top needs full-screen mode.
    
           •  The user interface, through prompts and help, intentionally
              implies that the delay interval is limited to tenths of a
              second.  However, you're free to set any desired delay.  If you
              want to see Linux at his scheduling best, try a delay of .09
              seconds or less.
    
              For this experiment, under x-windows open an xterm and maximize
              it.  Then do the following:
                . provide a scheduling boost and tiny delay via:
                    nice -n -10 top -d.09
                . keep sorted column highlighting _Off_ so as to
                  minimize path length
                . turn _On_ reverse row highlighting for emphasis
                . try various sort columns (TIME/MEM work well),
                  and normal or reverse sorts to bring the most
                  active processes into view
    
              What you'll see is a very busy Linux doing what he's always
              done for you, but there was no program available to illustrate
              this.
    
           •  Under an xterm using ‘white-on-black’ colors, on top's Color
              Mapping screen set the task color to black and be sure that
              task highlighting is set to bold, not reverse.  Then set the
              delay interval to around .3 seconds.
    
              After bringing the most active processes into view, what you'll
              see are the ghostly images of just the currently running tasks.
    
           •  Delete the existing rcfile, or create a new symlink.  Start
              this new version then type ‘T’ (a secret key, see topic 4c.
              Task Area Commands, SORTING) followed by ‘W’ and ‘q’.  Finally,
              restart the program with -d0 (zero delay).
    
              Your display will be refreshed at three times the rate of the
              former top, a 300% speed advantage.  As top climbs the TIME
              ladder, be as patient as you can while speculating on whether
              or not top will ever reach the top.
    
       **8b. Bouncing Windows**
           For these stupid tricks, top needs alternate-display mode.
    
           •  With 3 or 4 task displays visible, pick any window other than
              the last and turn idle processes _Off_ using the ‘i’ command
              toggle.  Depending on where you applied ‘i’, sometimes several
              task displays are bouncing and sometimes it's like an
              accordion, as top tries his best to allocate space.
    
           •  Set each window's summary lines differently: one with no memory
              (‘m’); another with no states (‘t’); maybe one with nothing at
              all, just the message line.  Then hold down ‘a’ or ‘w’ and
              watch a variation on bouncing windows  --  hopping windows.
    
           •  Display all 4 windows and for each, in turn, set idle processes
              to _Off_ using the ‘i’ command toggle.  You've just entered the
              "extreme bounce" zone.
    
       **8c. The Big Bird Window**
           This stupid trick also requires alternate-display mode.
    
           •  Display all 4 windows and make sure that 1:Def is the ‘current’
              window.  Then, keep increasing window size with the ‘n’
              interactive command until all the other task displays are
              "pushed out of the nest".
    
              When they've all been displaced, toggle between all
              visible/invisible windows using the ‘_’ command toggle.  Then
              ponder this:
                 is top fibbing or telling honestly your imposed truth?
    
       **8d. The Ol' Switcheroo**
           This stupid trick works best without alternate-display mode, since
           justification is active on a per window basis.
    
           •  Start top and make COMMAND the last (rightmost) column
              displayed.  If necessary, use the ‘c’ command toggle to display
              command lines and ensure that forest view mode is active with
              the ‘V’ command toggle.
    
              Then use the up/down arrow keys to position the display so that
              some truncated command lines are shown (‘+’ in last position).
              You may have to resize your xterm to produce truncation.
    
              Lastly, use the ‘j’ command toggle to make the COMMAND column
              right justified.
    
              Now use the right arrow key to reach the COMMAND column.
              Continuing with the right arrow key, watch closely the
              direction of travel for the command lines being shown.
    
                 some lines travel left, while others travel right
    
                 eventually all lines will Switcheroo, and move right
    


## 9\. BUGS



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


## 10\. SEE Also



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


* * *