Apparently this function does not return the database name given in the connection string. I tried this on apache 2.x/php4.3.x/pg7.4.x and apache 1.3.x/php5.x/pg8rc1 and saw this behavior on both setups.
(PHP 4, PHP 5)
pg_options — 获得和连接有关的选项
string pg_options ( resource
pg_options() 以字符串形式返回指定 PostgreSQL
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