Unix Command run successfully through PL/SQL but showing no impact in UNIX.

Question

Hi,
I am using Oracle 9i and Unix on my system and trying to execute a UNIX shell command through external procedure in C.
I created a shared lib (libextproc.so) for the following function.
int sysrun(char *command)
return system(command);
This function runs fine when caled through a driver function in C, meaning that the shared lib is fine.
In PL/SQL, I have used the following method to invoke a UNIX command:-
create or replace library shell_lib as '/home/ECETRAonsite/oracle/OraHome1/lib/libextproc.so';
create or replace function sysrun (syscomm in varchar2)
return binary_integer
as language C
name "sysrun"
library shell_lib
parameters(syscomm string);
Now when I call this PL/SQL function to invoke the command, it is run succesfully but does not create the file.
SQL>
1 declare
2 rc number;
3 begin
4 rc := sysrun('/bin/touch /home/ECETRAonsite/oracle/OraHome1/test/sach');
5 dbms_output.put_line('Return Code='||rc);
6* end;
SQL> /
Return Code=0
PL/SQL procedure successfully completed.
I have verified that the path for 'touch' is correct.
Following are my configuration files.
listener.ora
LISTENER =
(DESCRIPTION_LIST =
(DESCRIPTION =
(ADDRESS_LIST =
(ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC1))
(ADDRESS_LIST =
(ADDRESS = (PROTOCOL = TCP)(HOST =172.21.161.69 )(PORT = 1521)(KEY = ECTPRF))
SID_LIST_LISTENER =
(SID_LIST =
(SID_DESC =
(SID_NAME = extproc2)
(ORACLE_HOME = /home/ECETRAonsite/oracle/OraHome1)
(PROGRAM = extproc)
(ENVS = "EXTPROC_DLLS=ANY")
(SID_DESC =
(SID_NAME = ECTPRF)
(ORACLE_HOME = /home/ECETRAonsite/oracle/OraHome1)
(ENVS = "EXTPROC_DLLS=ANY")
tnsnames.ora
EXTPROC_CONNECTION_DATA =
(DESCRIPTION =
(ADDRESS_LIST =
(ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC1))
(CONNECT_DATA =
(SID = extproc2)
Please suggest what is lacking for this to work properly.
Thanks,

Answer 1

No need to create a C wrapper for that kernel call. Simply call the kernel SYSTEM() call direct.
The following works using 10.2.0.1 on HP-UX.
SQL> create or replace library libc as 'libc.2';
2 /
Library created.
SQL>
SQL>
SQL> create or replace function system( command IN string ) return binary_integer is
2 EXTERNAL
3 LIBRARY libc
4 NAME "system"
5 LANGUAGE C
6 CALLING STANDARD C
7 PARAMETERS (
8 command STRING
9 );
10 /
Function created.
SQL> show errors
No errors.
SQL>
SQL>
SQL> -- remove the test file
SQL> ! rm /tmp/plsql-test
SQL>
SQL> declare
2 rc integer;
3 begin
4 rc := system( '/usr/bin/touch /tmp/plsql-test' );
5 DBMS_OUTPUT.put_line( 'return code='||rc );
6 end;
7 /
return code=0
PL/SQL procedure successfully completed.
SQL>
SQL>
SQL>
SQL> -- display the test file
SQL> ! ls -l /tmp/plsql-test
-rw-r----- 1 oracle dba 0 May 17 14:36 /tmp/plsql-test
SQL>
You may need to define a different library on yours. The kernel shared lib is suppose to be libc.sl - for a reason I cannot recall anymore, I've changed it to use libc.2.
Oh yeah - the system call will be without any environment. Thus you cannot rely on any standard shell environment variables like PATH - you need to fully qualify executables and files (i.e. include the path).