EXTEND

 The EXTEND procedure opens an existing file, positions the  file
 buffer  after  the  last component, and prepares it for writing.
 It is commonly used to append to a file.


 Syntax:

    EXTEND( file_variable [[, file_name]]
            [[, ERROR := error-recovery]] );


 The 'file_variable' is the name of the file variable  associated
 with the output file.

 The 'file_name' is the name of the file to  be  associated  with
 the  'file_variable'.   If  the  file  was  opened with the OPEN
 procedure, the 'file_name' is ignored.

 The 'error-recovery' is the action  to  be  taken  if  an  error
 occurs during execution of the routine.

 The file can be in any mode before EXTEND is called to  set  the
 mode  to generation.  If the file is an external file and is not
 already open, EXTEND opens it using the defaults  for  the  OPEN
 procedure.

 After execution of EXTEND, the file is positioned after the last
 component,  and  EOF  and UFB return TRUE.  If the file does not
 exist, EXTEND does not create it, but returns an  error  at  run
 time.

 A call to EXTEND on a relative file  opened  for  direct  access
 positions the file after its last existing component.

 A call to EXTEND on an indexed file opened for random access  by
 key  positions the file after the last component relative to the
 primary key.

 See the "HP Pascal Language Reference  Manual"  for  a  complete
 description of the EXTEND procedure.