Get the names of the tables of a DB in postgresql

Based on the official PostgreSQL documentation about the information of the database schema , what could be done is to consult the information of the tables stored in information_schemasince in this there is a table called tablesin which the name of each table is found that makes up the database. The query would be the following:

SELECT table_name --seleccionamos solo la columna del nombre de la tabla
FROM information_schema.tables --seleccionamos la información del esquema 
WHERE table_schema='public' --las tablas se encuentran en el esquema publico
AND table_type='BASE TABLE'; --tiene que ser del tipo table ya que aqui se listan tambien las vistas 

In this way, the names of the tables that make up the database would be obtained, generating a result that can be iterated in some programming language.

another very useful and proven option; I have the same doubt as you.

=>\dt

or may be

=>SELECT * FROM pg_catalog.pg_tables;

credit to https://stackoverflow.com/questions/769683/show-tables-in-postgresql

Specifically, if what you are looking for is a procedure to perform any spontaneous action with those tables, I usually build a script on the fly with a very easy structure and it is not necessary to create a function, execute it and then delete it.

Using Juan Pinzón's query, the script would be as follows:

DO
$$
DECLARE
    _schema text;
    _table text;
BEGIN
    FOR _schema, _table IN
        SELECT table_schema, table_name
        FROM information_schema.tables
        -- No filtro por esquema 'public' porque yo uso muchos más esquemas
        WHERE table_type = 'BASE TABLE'
    LOOP
        -- En este bloque LOOP puedes introducir tu código para hacer lo que quieras
        -- con las tablas
        -- Usando las variables _schema, _table
        RAISE NOTICE 'Código a ejecutar con %, %', _schema, _table;
    END LOOP;

END
$$
;