Can I run a Unix shell when insert some record on a specific table?

Question

Can I run a Unix shell when insert some record on a specific table?
I need to run a Unix shell when a record be insert on a table. Is there a way in order to do that?
THanks,
Carlos.

Answer 1

1. Make a backup of the extproc.c file in the c:\orant\rdbms80\extproc
directory.
2. Create a file called extern.c in the c:\orant\rdbms80\extproc directory.
The "extern.c" file :
#include <oci.h>
#define NullValue -1
#include<stdio.h>
#include<string.h>
long __declspec(dllexport) OutputString(context ,
                         path , path_ind ,
                         message , message_ind,
                         filemode , filemode_ind ,
                         len , len_ind )
char *path;
char *message; 
char *filemode;
int len;
OCIExtProcContext *context;
short path_ind;
short message_ind;
short filemode_ind;
short len_ind;
FILE *file_handle;
int i ;
char str[3];
int value;
/* Check whether any parameter passing is null */
if (path_ind == OCI_IND_NULL || message_ind == OCI_IND_NULL ||
filemode_ind == OCI_IND_NULL || len_ind == OCI_IND_NULL ) {
text initial_msg = (text )"One of the Parameters Has a Null Value!!! ";
text *error_msg;
/* Allocate space for the error message text, and set it up.
We do not have to free this memory - PL/SQL will do that automatically. */
error_msg = OCIExtProcAllocCallMemory(context,
strlen(path) + strlen(initial_msg) + 1);
strcpy((char *)error_msg, (char *)initial_msg);
/*strcat((char *)error_msg, path); */
OCIExtProcRaiseExcpWithMsg(context, 20001, error_msg, 0);
/* OCIExtProcRaiseExcp(context, 6502); */
return 0;
/* Open the file for writing. */
file_handle = fopen(path, filemode);
/* Check for success. If not, raise an error. */
if (!file_handle) {
text initial_msg = (text )"Cannot Create file ";
text *error_msg ;
/* Allocate space for the error message text, and set it up.
We do not have to free this memory - PL/SQL will do that automatically. */
error_msg = OCIExtProcAllocCallMemory(context,
strlen(path) + strlen(initial_msg) + 1);
strcpy((char *)error_msg, (char *)initial_msg);
strcat((char *)error_msg, path);
OCIExtProcRaiseExcpWithMsg(context, 20001, error_msg, 0);
return 0;
i = 0;
while (i < len)
/* Read the hexadecimal value(1). */
str[0] = message;
     i++;
/* Read the hexadecimal value(2). */
str[1] = message[i];
/* Convert the first byte to the binary value. */
if (str[0] > 64 && str[0] < 71)
str[0] = str[0] - 55;
else
str[0] = str[0] - 48;
/* Convert the second byte to the binary value. */
if (str[1] > 64 && str[1] < 71)
str[1] = str[1] - 55;
else
str[1] = str[1] - 48;
/* Convert the hex value to binary (first & second byte). */
value = str[0] * 16 + str[1];
/* Write the binary data to the binary file. */
fprintf(file_handle,"%c",value);
          i++;
/* Output the string followed by a newline. */
/* fwrite(message,len,1,file_handle); */
/* Close the file. */
fclose(file_handle);
3. Use the make.bat available in the c:\orant\rdbms80\extproc directory. You
need to run vcvars32.bat file before running this batch file. This will
create a dll file.
4. Configure the tnsnames.ora and the listener.ora files.
The tnsnames.ora should contain the following entries.
extproc_connection_data.world =
(DESCRIPTION =
(ADDRESS =
(PROTOCOL = IPC)
(KEY = ORCL)
(CONNECT_DATA = (SID = extproc)
The listener.ora should contain the following entries.
# P:\ORANT\NET80\ADMIN\LISTENER.ORA Configuration File:p:\orant\net80\admin\listener.ora
# Generated by Oracle Net8 Assistant
LISTENER8 =
(ADDRESS = (PROTOCOL = TCP)(HOST = winnt_nsc)(PORT = 1521))
SID_LIST_LISTENER8=
(SID_LIST =
(SID_DESC =
(GLOBAL_DBNAME = winnt_nsc)
(SID_NAME = ORCL)
(SID_DESC =
(SID_NAME = extproc)
(PROGRAM = extproc)
5. Login from sqlplus and issue the following statements.
create library externProcedures as 'C:\orant\RDBMS80\EXTPROC\extern.dll';
Create or replace PROCEDURE OutputString(
p_Path IN VARCHAR2,
p_Message IN VARCHAR2,
p_mode in VARCHAR2,
p_NumLines IN BINARY_INTEGER) AS EXTERNAL
LIBRARY externProcedures
NAME "OutputString"
With context
PARAMETERS (CONTEXT,
p_Path STRING,
p_path INDICATOR,
p_Message STRING,
p_message INDICATOR,
p_mode STRING,
p_mode INDICATOR,
p_NumLines INT,
p_numlines INDICATOR);
This is the pl/sql block used to write the contents of the BLOB into a file.
Set serveroutput on before running it.
SQL> desc lob_tab;
Name Null? Type
C1 NUMBER
C2 BLOB
lob_tab is the table which contains the blob data.
declare
i1 blob;
len number;
my_vr raw(10000);
i2 number;
i3 number := 10000;
begin
-- get the blob locator
SELECT c2 INTO i1 FROM lob_tab WHERE c1 = 2;
-- find the length of the blob column
len := DBMS_LOB.GETLENGTH(i1);
dbms_output.put_line('Length of the Column : ' || to_char(len));
-- Read 10000 bytes at a time
i2 := 1;
if len < 10000 then
-- If the col length is < 10000
DBMS_LOB.READ(i1,len,i2,my_vr);
outputstring('p:\bfiles\ravi.bmp',rawtohex(my_vr),'wb',2*len);
-- You have to convert the data to rawtohex format. Directly sending the buffer
-- data will not work
-- That is the reason why we are sending the length as the double the size of the data read
dbms_output.put_line('Read ' || to_char(len) || 'Bytes');
else
-- If the col length is > 10000
DBMS_LOB.READ(i1,i3,i2,my_vr);
outputstring('p:\bfiles\ravi.bmp',rawtohex(my_vr),'wb',2*i3);
dbms_output.put_line('Read ' || to_char(i3) || ' Bytes ');
end if;
i2 := i2 + 10000;
while (i2 < len ) loop
-- loop till entire data is fetched
DBMS_LOB.READ(i1,i3,i2,my_vr);
dbms_output.put_line('Read ' || to_char(i3+i2-1) || ' Bytes ');
outputstring('p:\bfiles\ravi.bmp',rawtohex(my_vr),'ab',2*i3);
i2 := i2 + 10000 ;
end loop;
end;