assert.h(7POSIX) POSIX Programmer's Manual assert.h(7POSIX)
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.
assert.h — verify program assertion
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.h> header shall define the assert() macro. It refers to the macro NDEBUG which
is not defined in the header. If NDEBUG is defined as a macro name before the inclusion of
this header, the assert() macro shall be defined simply as:
#define assert(ignore)((void) 0)
Otherwise, the macro behaves as described in assert().
The assert() macro shall be redefined according to the current state of NDEBUG each time
<assert.h> is included.
The assert() macro shall be implemented as a macro, not as a function. If the macro defi‐
nition is suppressed in order to access an actual function, the behavior is undefined.
The following sections are informative.
The System Interfaces volume of POSIX.1‐2008, assert()
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 discrep‐
ancy 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 https://www.kernel.org/doc/man-pages/reporting_bugs.html .
IEEE/The Open Group 2013 assert.h(7POSIX)