Generate correct MIME header for FS file that allow browser download such file.

oracle_create_mime

DECLARE
  l_filename BFILE;
  v_export_dir VARCHAR2(2000);
  v_length integer;
  l_blob blob;
  des_offset number := 1;
  src_offset number := 1;
  x number;
BEGIN
  system_run('/path/to/report/generation/script.sh -r '); /*Run report generator script*/
  l_filename := bfilename('EXPORT_DIR','/expected_report_file_name.pdf'); /*Please create EXPORT_DIR in Oracle before use*/

  v_length := dbms_lob.getlength(l_filename);
  DBMS_LOB.createtemporary(l_blob, FALSE);
  dbms_lob.open(l_filename, dbms_lob.lob_readonly);
  DBMS_LOB.LOADBLOBFROMFILE(dest_lob=>l_blob, 
                            src_bfile=>l_filename, 
                            amount=>v_length,
                            dest_offset=>des_offset,
                            src_offset=>src_offset);

  owa_util.mime_header('application/pdf', FALSE );  
 
  -- set the size so the browser knows how much to download
  htp.p('Content-length: ' || v_length);
  -- the filename will be used by the browser if the users does a save as
  htp.p('Content-Disposition:  attachment; filename="expected_report_file_name.pdf"');
  -- close the headers            
  owa_util.http_header_close;
  -- download the BLOB
  wpg_docload.download_file(l_blob);
  DBMS_LOB.freetemporary(l_blob);
EXCEPTION WHEN OTHERS THEN
  DBMS_LOB.freetemporary(l_blob);
  RAISE;
END;