Oracle PL-SQL procedure for running OS script

oracle_system_run

CREATE DIRECTORY TMP AS '/tmp/';

create or replace 
PROCEDURE system_run(cmd IN varchar2)
IS
  script_file   varchar2(40) := 'my-temp-script.sh';
  script_data   varchar2(4000);
  MyFile        utl_file.file_type;
  d             varchar2(4000);
  dump_file     varchar2(40) := 'my-temp-file.dat';
  dump_type     utl_file.file_type;
BEGIN
  -- Open file
  MyFile := utl_file.fopen('TMP',script_file,'w');
  -- Write data to file
  script_data := '#!/bin/bash' || chr(10) || cmd||'>'||'/tmp/'||dump_file;
  utl_file.put_line(MyFile, script_data, FALSE);
  -- Close file
  utl_file.fflush(MyFile);
  utl_file.fclose(MyFile);
  -- Purge old logs, no fun anyway
  dbms_scheduler.purge_log(JOB_NAME=>'TEST_RUN');
  -- Execute script
  -- The job is created as disabled as
  -- we execute it manually and will
  -- drop itself once executed.
  dbms_scheduler.create_job(
    job_name   => 'TEST_RUN',
    job_type   => 'EXECUTABLE',
    job_action => '/bin/bash',
    number_of_arguments => 1,
    start_date => SYSTIMESTAMP,
    enabled    => FALSE);
  dbms_scheduler.set_job_argument_value('TEST_RUN', 1, '/tmp/'||script_file);
  dbms_scheduler.enable('TEST_RUN');
  -- Wait for the job to be executed
  -- usually done within 1 second but
  -- I set it to 2 just in case.
  dbms_lock.sleep(2);
  -- Open the output file and
  -- print the result.
  dump_type := utl_file.fopen('TMP',dump_file,'r');
  loop
    begin
      utl_file.get_line(dump_type,d);
      dbms_output.put_line(d);
    exception
      when others then
        exit;
    end;
  end loop;
  utl_file.fclose(dump_type);
  -- Clean up our temp files
  utl_file.fremove('TMP', script_file);
  utl_file.fremove('TMP', dump_file);
END;