The pam_open_session() function is used to indicate that an authenticated session has begun, after the user has been identified (see pam_authenticate()) and, if necessary, granted credentials (see pam_setcred()). It is used to inform the module that the user is currently in a session. It should be possible for the PAM library to open a session and close the same session from different applications.
flags may have the value
PAM_SILENT to indicate that no output be
generated as a result of this function call.
One of the loaded modules was unable to open a session for the user.
Note: Errors may be translated to text with pam_strerror().