write to syslog from pl/sql

External procedure interface can be used. I have not implemented the openlog() and closelog() calls (got a weird problem with that). The syslog() call works fine on its own though.

o/s: Kubuntu 11.10
Oracle XE 10.2.0.1

// call:
//    void syslog(int priority, const char *format, ...);
// library:
//    libc

SQL> create or replace library libc as
  2          '/lib/i386-linux-gnu/libc.so.6'
  3  /

Library created.

SQL> 
SQL> create or replace procedure WriteSysLog( priority binary_integer, message varchar2 ) is
  2          external
  3          library libc
  4          name "syslog"
  5          language C
  6          calling standard C
  7          parameters(
  8                  priority int,
  9                  message string
 10          );
 11  /

Procedure created.

SQL>
SQL> declare
  2          LOG_INFO        constant binary_integer := 6;
  3  begin
  4          WriteSysLog( LOG_INFO, 'All your syslogs messages are belong to us.' );
  5  end;
  6  /

PL/SQL procedure successfully completed.

SQL> 

And in +/var/log/syslog+ :

..
Feb  2 00:00:00 hostname extprocPLSExtProc: All your syslogs messages are belong to us.
..

Note you need a properly configured external procedure (EXTPROC) service in the local Listener, and a valid TNS alias for it in the local tnsnames.ora file. (local, as in local on the Oracle server where the PL/SQL code is executed)