ASSERT(3)                  POSIX Programmer's Manual                 ASSERT(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
       assert -- insert program diagnostics

SSYYNNOOPPSSIISS
       #include <assert.h>

       void assert(scalar _e_x_p_r_e_s_s_i_o_n);

DDEESSCCRRIIPPTTIIOONN
       The functionality described on this reference page is aligned with the
       ISO C standard. Any conflict between the requirements described here
       and the ISO C standard is unintentional. This volume of POSIX.1-2017
       defers to the ISO C standard.

       The _a_s_s_e_r_t() macro shall insert diagnostics into programs; it shall
       expand to a vvooiidd expression. When it is executed, if _e_x_p_r_e_s_s_i_o_n (which
       shall have a ssccaallaarr type) is false (that is, compares equal to 0),
       _a_s_s_e_r_t() shall write information about the particular call that failed
       on _s_t_d_e_r_r and shall call _a_b_o_r_t().

       The information written about the call that failed shall include the
       text of the argument, the name of the source file, the source file line
       number, and the name of the enclosing function; the latter are,
       respectively, the values of the preprocessing macros __FILE__ and
       __LINE__ and of the identifier __func__.

       Forcing a definition of the name NDEBUG, either from the compiler
       command line or with the preprocessor control statement ##ddeeffiinnee NDEBUG
       ahead of the ##iinncclluuddee _<_a_s_s_e_r_t_._h_> statement, shall stop assertions from
       being compiled into the program.

RREETTUURRNN VVAALLUUEE
       The _a_s_s_e_r_t() macro shall not return a value.

EERRRROORRSS
       No errors are defined.

       _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
       None.

AAPPPPLLIICCAATTIIOONN UUSSAAGGEE
       None.

RRAATTIIOONNAALLEE
       None.

FFUUTTUURREE DDIIRREECCTTIIOONNSS
       None.

SSEEEE AALLSSOO
       _a_b_o_r_t(), _s_t_d_i_n

       The Base Definitions volume of POSIX.1-2017, <<aasssseerrtt..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                            ASSERT(3)
