The frontend/backend authentication process is handled by PQconnectdb without any further intervention. The authentication method is now determined entirely by the DBA (see pga_hba.conf(5)). The following routines no longer have any effect and should not be used.
fe_getauthname Returns a pointer to static space containing whatever name the user has authenticated. Use of this routine in place of calls to getenv(3) or getpwuid(3) by applications is highly recommended, as it is entirely possible that the authenticated user name is not the same as value of the USER environment variable or the user's entry in /etc/passwd.
char *fe_getauthname(char* errorMessage)
fe_setauthsvc Specifies that libpq should use authentication service name rather than its compiled-in default. This value is typically taken from a command-line switch.
void fe_setauthsvc(char *name, char* errorMessage)Any error messages from the authentication attempts are returned in the errorMessage argument.