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 hostname of localhost matches both host (TCP)
and local (Unix domain socket) 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.)