Using OS Commands within PL/SQL

Question

How can I use Operating system commands from within PL/SQL procedures or functions? Kindly explain with an example.
Thanx,
SB

Answer 1

Previously we have used external procedures to use Windows kernel32.dll to start an external program. However this does not work on Oracle9i.
Instead I have modified an example in Java to acceive this. The following class can start an external program either synchronously or asynchronously and in synchronous mode it will return the programs output.
import java.io.*;
import java.util.*;
public class util
// Executes an operating system command. The command shall be fully qualified.
// The Java connects with silent login. No environment set-up files are run
// and no path is set. The mode can be "sync" or "async" for respectively
// synchronous and asynchronous execution
static public int OSCmd(String cmd, String mode, String[] output)
throws IOException, InterruptedException
System.out.println("OSCmd "+cmd+" ("+mode+")");
output[0]="";
// start command
Process proc = Runtime.getRuntime().exec(cmd);
if (mode.equals("sync"))
// get command's stdout and stderr
InputStream stdout = proc.getInputStream();
InputStream stderr = proc.getErrorStream();
String str;
// Stdout
BufferedReader br = new BufferedReader(new InputStreamReader(stdout));
while ((str = br.readLine()) != null)
output[0]+=str+"\n";
br.close();
// Stderr
br = new BufferedReader(new InputStreamReader(stderr));
while ((str = br.readLine()) != null)
output[0]+=str+"\n";
br.close();
// wait for command to terminate
proc.waitFor();
return proc.exitValue();
return 0;
You need the following permissions:
call dbms_java.grant_permission('COMMON', 'SYS:java.io.FilePermission', '<<ALL FILES>>', 'execute');
call dbms_java.grant_permission('COMMON', 'SYS:java.lang.RuntimePermission', 'writeFileDescriptor', '');
call dbms_java.grant_permission('COMMON', 'SYS:java.lang.RuntimePermission', 'readFileDescriptor', '');
And then create the Java stored procedure:
create or replace function os_cmd2(p_cmd varchar2, p_mode varchar2, p_output in out varchar2) return number
as language java
name 'util.OSCmd(java.lang.String, java.lang.String, java.lang.String[]) return int';