Section (3) pam_open_session
function sets up a user session for a previously successful
authenticated user. The session should later be terminated
with a call to pam_close_session(3).
It should be noted that the effective uid, geteuid(2). of the application should be of sufficient privilege to perform such tasks as creating or mounting the user_zsingle_quotesz_s home directory for example.
The flags argument is the binary or of zero or more of the following values:
Do not emit any messages.
Memory buffer error.
Session was successful created.