ASSERT(3P)                                          POSIX Programmer's Manual                                         ASSERT(3P)



PROLOG
       This  manual  page is part of the POSIX Programmer's Manual.  The Linux implementation of this interface may differ (con-
       sult 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  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 pre-
       processing 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(), stderr, the Base Definitions volume of IEEE Std 1003.1-2001, <assert.h>

COPYRIGHT
       Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2003  Edition,  Standard  for
       Information  Technology -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 6, Copy-
       right (C) 2001-2003 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.open-
       group.org/unix/online.html .



IEEE/The Open Group                                           2003                                                    ASSERT(3P)