无法连接到服务器/tmp/.s.PGSQL.5432

Question

我卸载并重新安装了psql并重新启动了我的电脑，因为有人建议了。但是，当我运行psql

时，我仍然会收到此错误消息

psql: could not connect to server: No such file or directory
    Is the server running locally and accepting
    connections on Unix domain socket "/tmp/.s.PGSQL.5432"?

我也改变了权限。我在/usr/local/var/postgres中看到的只是server.log。

postgres cannot access the server configuration file "/usr/local/var/postgres/postgresql.conf": No such file or directory
postgres cannot access the server configuration file "/usr/local/var/postgres/postgresql.conf": No such file or directory

我正在尝试为我的rails应用程序运行localhost，但我也得到了这个错误。