ASSERT
Section: POSIX Programmer's Manual (3P)
Updated: 2017
Page Index
PROLOG
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.
NAME
assert
--- insert program diagnostics
SYNOPSIS
#include <assert.h>
void assert(scalar expression);
DESCRIPTION
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
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.
RETURN VALUE
The
assert()
macro shall not return a value.
ERRORS
No errors are defined.
The following sections are informative.
EXAMPLES
None.
APPLICATION USAGE
None.
RATIONALE
None.
FUTURE DIRECTIONS
None.
SEE ALSO
abort(),
stdin
The Base Definitions volume of POSIX.1-2017,
<assert.h>
COPYRIGHT
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 .