As you might see (or may not see),  I  edit  my  gopher
          articles with TECO, which stands for Text Editor and COrrec‐
          tor.

               To use TECO, you may have to at  least  know  something
          about how a program is working.

               Traditionally, TECO program does  not  take  arguments,
          you just type:

          $ te

               in you shell prompt. Then TECO will prompt  a  starmark
          (*), indicates it is ready to work.

               Now we can just play around with it. Remember, TECO  is
          somewhat  dangerous  for  UNIX, because you can easily erase
          some data and you may never recover your precious data. When
          TECO  was used in the old days, popular systems like TOPS-10
          have a fancy global version control at file system level, so
          one would hardly ever be worried about deleting some files.

               Now we type I:

          *I_

               Underscore(_) represents the place  of  cursor.  TECO's
          commands  are  not sensetive, so one might type lower case i
          instead of I.

               Then you just type something. For example:

          *Invsalnxzncnljsf

               When finished typing, press Esc(^[) key twice.

          *Invsalnxzncnljsf$$
          *

               You will see TECO display ^[ as a dollar sign($).

               Stroke ^[ one time means  end  a  command,  and  stroke
          twice execute the commands.  If commands succeed, TECO would
          just emit a newline and a * to prompt for new commands.