Connecting to Postgres Database from C Program

Hi Experts,

I need to connect to the Postgres database from a C.  I was able to connect to the database.  Then I tried to execute the following command

create function sendevent() returns trigger as '/usr/lib/pgsql/libevent.so' language 'C';

When I do that I am getting the error message " permission denied for language c"

What am I doing wrong?  Also,  would it be possible to connect from a C++ program?

This is how I am building my program.
gcc -I/usr/include -I/usr/include/libxml2 -I/usr/include/pgsql/server -g -c ConnectDB.c
gcc  -I/usr/include -I/usr/include/libxml2 -I/usr/include/pgsql/server -g -o conn -L/usr/lib -lpq ConnectDB.o
ambuliAsked:
Who is Participating?
I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

ambuliAuthor Commented:
Hmm.  some web reference points out that I need to have super user privileges when I do this.  Is it correct?
0
ShineOnCommented:
That would likely be it.
0
ShineOnCommented:
If what you found did the trick, post your solution and post a free question in Community Support asking to have this closed with points refunded.  Be sure to include a link to this question.
0
Cloud Class® Course: Amazon Web Services - Basic

Are you thinking about creating an Amazon Web Services account for your business? Not sure where to start? In this course you’ll get an overview of the history of AWS and take a tour of their user interface.

ivanovnCommented:
You need to have USAGE privilege enabled for the user that's attempting to connect using the C language.
You can do this by granting the USAGE privilege as follows:

GRANT USAGE ON LANGUAGE langname TO username
0
ambuliAuthor Commented:
Thanks ivanovn.  But when I do that, I am getting an error message saying

ERROR:  language "c" is not trusted

0
ivanovnCommented:
Yes, C language is not trusted in PostgreSQL because of possible security issues (such as the ability of any user to execute C functions on your database).

However, I believe you can fix this if you execute the following:
UPDATE pg_language
SET lanpltrusted = true
WHERE lanname = 'c';
0

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
C++

From novice to tech pro — start learning today.

Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.