Can't Connect to PostgreSQL with PHP pg_connect()

EDIT: I just realized that this question may be better suited to ServerFault. Instead of copying it, a moderator please move it over? Thanks.

I've checked php-info, and the Postgresql extension is there (pg_connect() is not undefined). I am also able to connect to postgresql using psql on localhost (I've edited my pg_hba.conf file appropriately). Here is the code that's not working:

<?php
$dbconn = pg_connect("host=localhost port=5432 dbname=mydb user=myuser password=mypass") or die('Could not connect: ' . pg_last_error());
?>

This code simply results in "Could not connect: " being displayed in the browser.

I checked my apache log, and here's the relevant error message:

PHP Warning:  pg_connect() [<a href='function.pg-connect'>function.pg-connect</a>]: 
Unable to connect to PostgreSQL server: could not connect to server: Permission 
denied\n\tIs the server running on host &开发者_如何学JAVA;quot;localhost&quot; and accepting\n\tTCP/IP 
connections on port 5432?

How can I fix/debug this?

Edit: I'm on Centos 5.4 btw.

could not connect to server: Permission denied

Edit: I'm on Centos 5.4 btw.

Check /var/log/audit/audit.log. Chances are that you're hitting a SELinux rule.