The EOLN function tests for the end-of-line marker within a text
  file and returns a Boolean value.

  Syntax:

     EOLN [[( file_variable )]]

  The 'file_variable' is the name of a  file  variable  associated
  with a text file.  If you omit the name of the file, the default
  is INPUT.

  The file must be in inspection mode and EOF  must  return  FALSE
  before EOLN is called.  EOLN leaves the file in inspection mode.

  The Boolean EOLN function returns TRUE when the file pointer  is
  positioned  after  the  last character in a line.  When the EOLN
  function  returns  TRUE,  the  file  buffer  contains  a   blank
  character.

  The EOLN function returns FALSE when the last component  in  the
  line  is  read  into the file buffer.  Another character must be
  read to cause EOLN to return TRUE and to cause the  file  buffer
  to  be  positioned  at the end-of-line marker following the last
  character of the line.  If  you  use  the  EOLN  function  on  a
  nontext file, an error occurs.

  See the "HP Pascal Language Reference  Manual"  for  a  complete
  description of the EOLN function.