BlockWrite procedure

  DECLARATION:  BlockWrite(var F : File; var Buf; Count : Word
                          [; var Result : Word])

      PURPOSE:  Writes one or more records from a variable.

         UNIT:  System

      REMARKS:  F is an untyped file variable, Buf is any variable, count
                is an expression of type word, and Result is a variable of
                type word.

                Writes Count or less records to the file F from
                memory, starting at the first byte occupied by Buf.

                The actual number of complete records written is returned in
                the optional parameter Result.  If Result is not specified,
                an I/O error will occur if the number of records written is
                not equal to Count.

                The current file position is advanced by Result records.

 RESTRICTIONS: File to be written must be open

      EXAMPLE: program copyfile;

                Var
                   InFile, OutFile : File;
                   QtyRead, QtyWritten : Word;
                   buf : Array[1..2048] of Char;

                Begin
                   Assign(InFile, "Input.fle");     { Literal filename 'input.fle' }
                   ReSet(InFile, 1);
                   Assign(OutFile, "Output.fle");   { Literal filename 'output.fle' }
                   ReWrite(OutFile, 1);
                   Repeat
                      BlockRead(InFile, buf, SizeOf(buf), QtyRead);
                      BlockWrite(OutFile, buf, QtyRead, QtyWritten);
                   Until (QtyRead = 0) or (QtyWritten <> QtyRead);
                   Close(InFile);
                   Close(OutFile);
                End.