The file .pgpass in a user's home directory or the file referenced by PGPASSFILE can contain passwords to be used if the connection requires a password (and no password has been specified otherwise). On Microsoft Windows the file is named %APPDATA%\postgresql\pgpass.conf (where %APPDATA% refers to the Application Data subdirectory in the user's profile).
This file should contain lines of the following format:
hostname : port : database : username : password
Each of the first four fields may be a literal value, or * , which matches anything. The password field from the first line that matches the current connection parameters will be used. (Therefore, put more-specific entries first when you are using wildcards.) If an entry needs to contain : or \ , escape this character with \ . A host name of localhost matches both TCP (hostname localhost ) and Unix domain socket ( pghost empty or the default socket directory) connections coming from the local machine.
The permissions on .pgpass must disallow any access to world or group; achieve this by the command chmod 0600 ~/.pgpass . If the permissions are less strict than this, the file will be ignored. (The file permissions are not currently checked on Microsoft Windows, however.)