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