how to execute a C program via trigger ?

Hi,

I am using Red Hat 6.1 + PostgreSQL 7.0.3. All of
my
applications are developed by C and ECPG. I would
like to know how to execute a C program by Trigger,for
example:

1. I have a program my_c_program.c shuch as:

#include <stdio.h>
main()
{
printf("Hello World !\n");
}

2. I create a table foo by following command

CREATE TABLE foo
(
x int4
);

3. create a trigger foo_trig :

create trigger foo_trig after update
on foo for each row execute procedure sql_c();

4. I don't know how to design sql_c(), can anyone
give a small plpsql program that can execute
my_c_program?

regards, S.F. Lee

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