external procedure and gcc (newbie)

From: Matt <matthew.ramadanovic_at_yale.edu>
Date: 8 Mar 2005 20:27:56 -0800
Message-ID: <1110342476.509173.151220@z14g2000cwz.googlegroups.com>

Folks,

        Has anyone ever sucessfully compiled an external procedure for Oracle 9i on Solaris using gcc? I attempted to follow the documentation but have not been sucessful. My hunch is that it is the compiler but I'd like to find out for sure if I really need a $3000 compiler to compile a (4 line) stored procedure. My main support for this rather lame conclusion comes from the fact that neither my program nor the demos will compile properly using the demo_rdbms.mk makefile. Please, say it ain't so!

-Matt

If you are interested, here is what I am doing and the errors I am getting. I upgraded gcc from 2.9x to 3.4.3 but have the same errors.

The stored procedure in question compiles when I do this :

        gcc execute_cmd.c -o execute_cmd.o

Once compiled "execute_cmd.o xxx" outputs "Your argument was xxx"

If I compile it the way they mention in this tutorial (and the Oracle documentation) :

        http://home.clara.net/dwotton/dba/oracle_extn_rtn3.htm

The executable no longer runs from the commandline :

	gcc -c execute_cmd.c
        ./execute_cmd.o
	chmod 777 ./execute_cmd.o
	Cannot execute binary file

Here is execute_cmd.c

	#include <stdio.h>
	#include <string.h>
	int main (int argc, char *argv[])
	{
	     if (argc == 2) {
	       printf("Your argument was %s\n", argv[1]);
	     }
	}
	void execute_cmd( char* cmd )
	{
	       system(cmd);
	}

Ignoring this bad omen I attempte to keep going. According to the doco, you have to use the demo_rdbms.mk makefile to compile the external procedure. I set LD_LIBRARY_PATH explicitly to avoid "wrong ELF class: ELFCLASS64" errors and then compile.

	LD_LIBRARY_PATH=/export/home/oracle/lib32:$LD_LIBRARY_PATH
	export LD_LIBRARY_PATH
	gcc -c execute_cmd.c
	make -f $ORACLE_HOME/rdbms/demo/demo_rdbms.mk extproc_callback

SHARED_LIBNAME=execute_cmdlib.so OBJS=execute_cmd.o

I get this error from the make :

        /usr/ccs/bin/ld -G -z text -L/export/home/oracle/product/9.2.0/lib
-R/export/home/oracle/product/9.2.0/lib -o execute_cmdlib.so
execute_cmd.o /export/home/oracle/product/9.2.0/lib/libpls9.a -lclntsh  `cat /export/home/oracle/product/9.2.0/lib/sysliblist`
-R/export/home/oracle/product/9.2.0/lib -laio -lposix4 -lkstat -lm
-lthread

	Text relocation remains                         referenced
	    against symbol           offset      in file
	<unknown>                    0x28        execute_cmd.o
	<unknown>                    0x2c        execute_cmd.o
	printf                       0x34        execute_cmd.o
	system                       0x54        execute_cmd.o
	ld: fatal: relocations remain against allocatable but non-writable
sections
	*** Error code 1
	make: Fatal error: Command failed for target `extproc_callback'

This error goes away if I compile with this commandline :

        gcc -c -fPIC execute_cmd.c

If I create the relevant stored procedures grants and stuff in oracle it doesn't (not surprisingly) execute. Instead attempts to use the external procedure like so

	    DECLARE
	       cmd varchar2(200);
	    BEGIN
	       cmd := '/bin/touch /tmp/yyy';
	       execute_cmd(cmd);
	    END;

Yeilds oracle erros :

	ORA-28595: Extproc agent : Invalid DLL Path
	ORA-06512: at "SYSTEM.EXECUTE_CMD", line 0
	ORA-06512: at line 9

Received on Tue Mar 08 2005 - 22:27:56 CST