Porting from MySql - meta data issues

Hi folks

I'm porting quite a big PHP application from MySql and have hit an issue.

I have a number of PHP functions in the app which return meta-info about
the data structure:

list_databases( ) ;
list_tables( $database_name ) ;
list_field_names( $table_name ) ;
is_existing_field( $table_name ) ;

With MySql, this info is readily available using the various SHOW queries,
but I can't figure out how to do this with Postgres.

The only option I have come up with is to shell out to psql, run \l and \d
commands, and use a regex to parse the strings returned. Clearly, this
would be a bit of a hack, and not resource efficient.

Can any kind person suggest a more effective approach? I am brand new to
Postgres, and doing this under considerable time pressure, so apologies if
I am missing anything obvious - I can't find anything in the docs, or in
the articles on porting from MySQL...

Geoff Caplan
Advantae Ltd