How to find the output file name and path?

When ever any Concurrent Request is submitted, log and output files are stored in $APPLCSF/$APPLOG and $APPLCSF/$APPLOUT directories respectively.

 SELECT LOGFILE_NAME, OUTFILE_NAME
   FROM fnd_concurrent_requests
  WHERE  request_id = &conc_request_id;

Create file in unix system with 'Hello World'

Declare
file1 utl_file.file_type;
Begin
file1:= utl_file.fopen('MY_DIR','x.txt','r');
utl_file.put_line(file1,'Hello World' );
utl_file.fclose(file1);
end;
/
show err;