su - visudoDescription what each column means
#----------------------------------------------- # john ALL = (ALL:ALL) NOPASSWD: ALL # ^ ^ ^ ^ ^ # | | | | | # user | all users| | # host | all commands # all groups #----------------------------------------------- oracle ALL=(ALL) NOPASSWD: ALL
sudo dnf install https://dl.fedoraproject.org/pub/epel/epel-release-latest-8.noarch.rpm
2. Install btop Once the repository is enabled, you can install btop (the executable name for🛈 This command adds the EPEL repository configuration to your system.
btop++) using dnf:
sudo dnf install btop3. Run
btop:
btop
SQL> DEFINE s_container='CDB$ROOT'; --DEFINE s_container='PDB1'; --DEFINE s_container='PDB2'; ALTER SESSION SET container = &&s_container; show con_name
/*
Build by Vadim Loevski of Quest Software.
*/
CREATE OR REPLACE AND RESOLVE JAVA SOURCE NAMED "UTLcmd" AS
import java.lang.Runtime;
public class UTLcmd
{
public static void execute (String command)
{
try
{
Runtime rt = java.lang.Runtime.getRuntime();
rt.exec(command);
}
catch(Exception e)
{
System.out.println(e.getMessage());
return;
}
}
}
/
CREATE OR REPLACE PACKAGE UTLcmd IS
PROCEDURE execute (cmd IN VARCHAR2) AS LANGUAGE JAVA NAME
'UTLcmd.execute(java.lang.String)';
END;
/
/*======================================================================
| Supplement to the fifth edition of Oracle PL/SQL Programming by Steven
| Feuerstein with Bill Pribyl, Copyright (c) 1997-2009 O'Reilly Media, Inc.
| To submit corrections or find more code samples visit
| http://oreilly.com/catalog/9780596514464/
*/
CREATE OR REPLACE AND RESOLVE JAVA SOURCE NAMED "UTLcmd" AS
import java.lang.Runtime;
import java.lang.Process;
import java.io.BufferedReader;
import java.io.InputStreamReader;
public class UTLcmd
{
public static void execute (String command)
{
try
{
Runtime rt = java.lang.Runtime.getRuntime();
Process proc = rt.exec(command);
BufferedReader stdInput = new BufferedReader(new
InputStreamReader(proc.getInputStream()));
BufferedReader stdError = new BufferedReader(new
InputStreamReader(proc.getErrorStream()));
// Read the output from the command
System.out.println("Here is the standard output of the command:\n");
String s = null;
while ((s = stdInput.readLine()) != null) {
System.out.println(s);
}
// Read any errors from the attempted command
System.out.println("Here is the standard error of the command (if any):\n");
while ((s = stdError.readLine()) != null) {
System.out.println(s);
}
}
catch(Exception e)
{
System.out.println(e.getMessage());
return;
}
}
}
/
CREATE OR REPLACE PACKAGE UTLcmd IS
PROCEDURE execute (cmd IN VARCHAR2) AS LANGUAGE JAVA NAME
'UTLcmd.execute(java.lang.String)';
END;
/
🛈 Create Java source "UTLcmd" and PL/SQL package ULTcmd in required schema (SCOTT for example). In this article both versions like "Original" & "Improved with read stdin, stdout, stderr outputs" was created and tested in SYS/SYSTEM schemas, in this case provide next grant to required user/schema to able execute PL/SQL UTLcmd package:
GRANT EXECUTE ON UTLcmd TO SCOTT;
CALL DBMS_JAVA.SET_OUTPUT (1000000);
exec UTLcmd.execute('du -hs /u01');
Here is the standard output of the command: 141G /u01
exec UTLcmd.execute('ls -lht /u01');
Here is the standard output of the command: total 24K drwxr-xr-x 9 oracle oinstall 4.0K Jan 26 2026 appNext command don't works, I don't know why but looks like it don't understand "*"
exec UTLcmd.execute('du -hs /u01/*');
Here is the standard output of the command: Here is the standard error of the command (if any): /bin/du: cannot access '/u01/*': No such file or directory
CREATE OR REPLACE AND COMPILE JAVA SOURCE NAMED "FileListHandler" AS
import java.io.File;
import java.lang.Exception;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.sql.Array;
import oracle.jdbc.OracleConnection;
import oracle.jdbc.OracleDriver;
public class FileListHandler
{
public static Array list (String path) throws Exception {
Path directory = Paths.get(path);
if (!Files.isDirectory(directory))
throw new Exception("path argument does not reference a directory (" + path + ")");
File[] files = directory.toFile().listFiles();
OracleConnection connection = (OracleConnection)(new OracleDriver()).defaultConnection();
return connection.createOracleArray("T_VARCHAR2_ARR", files);
}
};
/
CREATE OR REPLACE TYPE t_varchar2_arr AS TABLE OF VARCHAR2(500); / CREATE OR REPLACE PACKAGE file_list_api AS FUNCTION list (p_path IN VARCHAR2) RETURN t_varchar2_arr AS LANGUAGE JAVA NAME 'FileListHandler.list (java.lang.String) return java.sql.Array'; END file_list_api; /Example of using:
SELECT * FROM table(FILE_LIST_API.list ('/u01/app/oracle/admin/orcl/adump/'));
Another implementing of FILE_LIST_API.list PL/SQL function in fDelete PL/SQL function as wrapper of Java JDelete.delete method for delete files from OS
CREATE OR REPLACE AND RESOLVE JAVA SOURCE NAMED "JDeleteFile" AS
import java.io.File;
public class JDelete {
public static int delete (String fileName) {
File myFile = new File (fileName);
boolean retval = myFile.delete();
if (retval) return 1; else return 0;
}
}
/
Create PL/SQL function fDelete as wrapper of Java JDelete.delete method
CREATE FUNCTION fDelete (file IN VARCHAR2) RETURN NUMBER AS LANGUAGE JAVA NAME 'JDelete.delete (java.lang.String) return int';Example of using:
SQL> EXEC DBMS_OUTPUT.PUT_LINE (fdelete('/u01/app/oracle/admin/orcl/adump/ora_some_file.aud'));
Before use fDelete function to avoid file permissions errors like:
ERROR at line 1: ORA-29532: Java call terminated by uncaught Java exception: java.security. AccessControlException: the Permission (java.io.FilePermission /u01/app/oracle/admin/orcl/adump/ora_some_file.aud delete) has not been granted to SCOTT. The PL/SQL to grant this is dbms_java.grant_permission( 'SCOTT', 'SYS:java.io.FilePermission', '/u01/app/oracle/admin/orcl/adump/ora_some_file.aud', 'delete' )need grants permission to access files in a required directory:
CALL DBMS_JAVA.grant_permission( 'SYSTEM', 'SYS:java.io.FilePermission', '/u01/app/oracle/admin/orcl/adump/*', 'read,write,delete' );fDelete function can delete just concrete specified file name (names which you know), if you want delete all files *.aud in directory then need use FILE_LIST_API.list described in List Files in a Directory From PL/SQL and SQL using Java class FileListHandler to get all file names list:
DECLARE
res pls_integer;
BEGIN
FOR rec in (SELECT * FROM table(FILE_LIST_API.list ('/u01/app/oracle/admin/orcl/adump/')) where rownum <= 10000)
LOOP
res := fdelete(rec.column_value);
/*
if res = 1 then
DBMS_OUTPUT.PUT_LINE (rec.column_value || ' is ' || 'deleted');
else
DBMS_OUTPUT.PUT_LINE (rec.column_value || ' ' || 'not found/error');
end if;
*/
END LOOP;
END;
/
Note: Oracle9i Database Release 2 introduced an enhanced version of the
UTL_FILE package that, among other things, allows you to delete a file
using the UTL_FILE.FREMOVE procedure. It also supports file copying
(FCOPY) and file renaming (FRENAME).