This manual page is part of the POSIX Programmer's Manual. The Linux
implementation of this interface may differ (consult the
corresponding Linux manual page for details of Linux behavior), or
the interface may not be implemented on Linux.
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.1‐2008 defers to the ISO C standard.
The assert() macro shall insert diagnostics into programs; it shall
expand to a void expression. When it is executed, if expression
(which shall have a scalar type) is false (that is, compares equal to
0), assert() shall write information about the particular call that
failed on stderr and shall call abort().
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 #define
NDEBUG ahead of the #include <assert.h> statement, shall stop
assertions from being compiled into the program.
Portions of this text are reprinted and reproduced in electronic form
from IEEE Std 1003.1, 2013 Edition, Standard for Information
Technology -- Portable Operating System Interface (POSIX), The Open
Group Base Specifications Issue 7, Copyright (C) 2013 by the
Institute of Electrical and Electronics Engineers, Inc and The Open
Group. (This is POSIX.1-2008 with the 2013 Technical Corrigendum 1
applied.) 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.unix.org/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
IEEE/The Open Group 2013 ASSERT(3P)