External c program call from plsql

Question

hi,
my db version is:
Oracle Database 11g Enterprise Edition Release 11.2.0.1.0 - Production
entry in my listener.ora file
===========================
# listener.ora Network Configuration File: /u01/app/oracle/product/11.2.0/dbhome_1/network/admin/listener.ora
# Generated by Oracle configuration tools.
SID_LIST_LISTENER =
(SID_LIST =
(SID_DESC =
(PROGRAM = extproc)
(SID_NAME = PLSExtProc)
(ORACLE_HOME = /u01/app/oracle/product/11.2.0/dbhome_1)
(SID_DESC =
(GLOBAL_DBNAME = orcl)
(ORACLE_HOME = /u01/app/oracle/product/11.2.0/dbhome_1)
(SID_NAME = orcl)
LISTENER =
(DESCRIPTION_LIST =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = TCP)(HOST = hostname)(PORT = 1521))
(DESCRIPTION =
(ADDRESS = (PROTOCOL = IPC)(KEY = extproc0))
ADR_BASE_LISTENER = /u01/app/oracle
entry in tnsnames.ora file:
===============================
# tnsnames.ora Network Configuration File: /u01/app/oracle/product/11.2.0/dbhome_1/network/admin/tnsnames.ora
# Generated by Oracle configuration tools.
EXTPROC_CONNECTION_DATA =
(DESCRIPTION =
(ADDRESS_LIST =
(ADDRESS = (PROTOCOL = IPC)(KEY = extproc0))
(CONNECT_DATA =
(SERVICE_NAME = orcl.example.com)
listener is running perfectly.
created c program,
compile the program by gcc -c <filename>
ld -shared -o <filename.so> <filename.o>
cp <filename.so> $ORACLE_HOME/bin
create library & function from db. when I am invoking this function it is throwing error message:
ORA-28546: connection initialization failed, probable Net8 admin error
tnx in advance

Answer 1

Here's a working example (11.2.0.3 using Oracle Linux 5.9):
SQL> !cat test.c
#include <ctype.h>
int upcase(char *istr, char *ostr){
        int i = 0;
        while(istr){
ostr[i] = toupper(istr[i]);
i++;
return 0;
SQL>
SQL> --// compile
SQL> ! gcc -fPIC -c test.c
SQL> --// result
SQL> ! ls -l test*
-rw-r--r-- 1 oracle oinstall 140 Jan 26 18:40 test.c
-rw-r--r-- 1 oracle oinstall 1480 Jan 26 18:48 test.o
SQL>
SQL> --// create shared object
SQL> ! ld -shared -o libtest.so test.o
SQL>
SQL> ! file libtest.so
libtest.so: ELF 64-bit LSB shared object, AMD x86-64, version 1 (SYSV), not stripped
SQL>
SQL> --// wrapper library and function
SQL> create or replace library libtest as '/home/oracle/sql/libtest.so';
2 /
Library created.
SQL>
SQL> create or replace function upcase( instr in varchar2, outstr out varchar2 ) return binary_integer is
2 external
3 library libtest
4 name "upcase"
5 language C
6 calling standard C
7 parameters(
8 instr string,
9 outstr string
10 )
11 ;
12 /
Function created.
SQL>
SQL> declare
2 str1 varchar2(20);
3 str2 varchar2(20);
4 rc binary_integer;
5 begin
6 str1 := 'hello world';
7 rc := upcase( str1, str2 );
8 dbms_output.put_line( 'rc='||rc||' instr='||str1||' outstr='||str2 );
9 end;
10 /
rc=0 instr=hello world outstr=HELLO WORLD
PL/SQL procedure successfully completed.
SQL>
The following 2 configuration settings are needed - in the +listener.ora+ (server) and the +tnsnames.ora+ (client).
For the Listener - add the ADDRESS line for EXTPROC to the LISTENER config, and add the EXTPROC SID entry to the SID list.LISTENER=
(DESCRIPTION=
(ADDRESS_LIST=
(ADDRESS=(PROTOCOL=ipc)(KEY=extproc))
SID_LIST_LISTENER =
(SID_LIST =
(SID_DESC =
(SID_NAME = PLSExtProc)
(ORACLE_HOME= <insert oracle home here> )
(PROGRAM = extproc)
(ENVS = "EXTPROC_DLLS=ANY")
The client needs to have a TNS alias that defines how to contact EXTPROC. This is done in +tnsnames.ora+:EXTPROC_CONNECTION_DATA =
(DESCRIPTION=
(ADDRESS=(PROTOCOL=ipc)(KEY=extproc))
(CONNECT_DATA=(SID=plsextproc))
Are you using RAC? if so, I do not think IPC connections are allowed by default between an Oracle db  server process and the Grid listener process. In which case, you can create an IPC only listener in the Oracle o/s user.