how can I run command line or shell script in Oracle

Please help me to create one text file to save all file names in directory
To put all filenames.dat into one file called datNames.txt I wrote a procedure as
create or replace
procedure host(cmd in varchar2 )
as
status number;
begin
dbms_pipe.pack_message( cmd );
status := dbms_pipe.send_message( 'HOST_PIPE' );
if ( status <> 0 ) then raise_application_error( -20001, 'Pipe error' );
end if;
end;
---------------------
I run the procedure in PL/SQL as
begin
  host('dir/b c:\dataloader\upload\*.dat > c:\dataloader\upload\datNames.txt');
end;
There is not error but it can not create c:\dataloader\upload\datNames.txt' eventhough I have granted write permission on the directory. But when I run it in MS DOs, It run OK.
Another question, I use 'dir/b c:\dataloader\upload\*.dat > c:\dataloader\upload\datNames.txt'  to run on window but if I want run  the procedure on Linux so Which shell script will be used to replace the MS DOS command line?