MQ_GETATTR(3)              POSIX Programmer's Manual             MQ_GETATTR(3)



PPRROOLLOOGG
       This manual page is part of the POSIX Programmer's Manual.  The OS
       implementation of this interface may differ (consult the corresponding
       OS manual page for details of OS behavior), or the interface may not be
       implemented on OS.

NNAAMMEE
       mq_getattr -- get message queue attributes (RREEAALLTTIIMMEE)

SSYYNNOOPPSSIISS
       #include <mqueue.h>

       int mq_getattr(mqd_t _m_q_d_e_s, struct mq_attr *_m_q_s_t_a_t);

DDEESSCCRRIIPPTTIIOONN
       The _m_q___g_e_t_a_t_t_r() function shall obtain status information and
       attributes of the message queue and the open message queue description
       associated with the message queue descriptor.

       The _m_q_d_e_s argument specifies a message queue descriptor.

       The results shall be returned in the mmqq__aattttrr structure referenced by
       the _m_q_s_t_a_t argument.

       Upon return, the following members shall have the values associated
       with the open message queue description as set when the message queue
       was opened and as modified by subsequent _m_q___s_e_t_a_t_t_r() calls: _m_q___f_l_a_g_s.

       The following attributes of the message queue shall be returned as set
       at message queue creation: _m_q___m_a_x_m_s_g, _m_q___m_s_g_s_i_z_e.

       Upon return, the following members within the mmqq__aattttrr structure
       referenced by the _m_q_s_t_a_t argument shall be set to the current state of
       the message queue:

       _m_q___c_u_r_m_s_g_s
                 The number of messages currently on the queue.

RREETTUURRNN VVAALLUUEE
       Upon successful completion, the _m_q___g_e_t_a_t_t_r() function shall return
       zero. Otherwise, the function shall return -1 and set _e_r_r_n_o to indicate
       the error.

EERRRROORRSS
       The _m_q___g_e_t_a_t_t_r() function may fail if:

       EEBBAADDFF  The _m_q_d_e_s argument is not a valid message queue descriptor.

       _T_h_e _f_o_l_l_o_w_i_n_g _s_e_c_t_i_o_n_s _a_r_e _i_n_f_o_r_m_a_t_i_v_e_.

EEXXAAMMPPLLEESS
       See _m_q___n_o_t_i_f_y().

AAPPPPLLIICCAATTIIOONN UUSSAAGGEE
       None.

RRAATTIIOONNAALLEE
       None.

FFUUTTUURREE DDIIRREECCTTIIOONNSS
       None.

SSEEEE AALLSSOO
       _m_q___n_o_t_i_f_y(), _m_q___o_p_e_n(), _m_q___s_e_n_d(), _m_q___s_e_t_a_t_t_r(), _m_s_g_c_t_l(), _m_s_g_g_e_t(),
       _m_s_g_r_c_v(), _m_s_g_s_n_d()

       The Base Definitions volume of POSIX.1-2017, <<mmqquueeuuee..hh>>

CCOOPPYYRRIIGGHHTT
       Portions of this text are reprinted and reproduced in electronic form
       from IEEE Std 1003.1-2017, Standard for Information Technology --
       Portable Operating System Interface (POSIX), The Open Group Base
       Specifications Issue 7, 2018 Edition, Copyright (C) 2018 by the
       Institute of Electrical and Electronics Engineers, Inc and The Open
       Group.  In the event of any discrepancy between this version and the
       original IEEE and The Open Group Standard, the original IEEE and The
       Open Group Standard is the referee document. The original Standard can
       be obtained online at http://www.opengroup.org/unix/online.html .

       Any typographical or formatting errors that appear in this page are
       most likely to have been introduced during the conversion of the source
       files to man page format. To report such errors, see
       https://www.kernel.org/doc/man-pages/reporting_bugs.html .



IEEE/The Open Group                  2017                        MQ_GETATTR(3)
