assert(3) [freebsd man page]

ASSERT(3)						   BSD Library Functions Manual 						 ASSERT(3)

NAME

     assert -- expression verification macro

SYNOPSIS

     #include <assert.h>

     assert(expression);

DESCRIPTION

     The assert() macro tests the given expression and if it is false, the calling process is terminated.  A diagnostic message is written to
     stderr and the function abort(3) is called, effectively terminating the program.

     If expression is true, the assert() macro does nothing.

     The assert() macro may be removed at compile time by defining NDEBUG as a macro (e.g., by using the cc(1) option -DNDEBUG).

EXAMPLES

     The assertion:

	   assert(1 == 0);

     generates a diagnostic message similar to the following:

	   Assertion failed: (1 == 0), function main, file assertion.c, line 100.

SEE ALSO

     abort(3)

STANDARDS

     The assert() macro conforms to ISO/IEC 9899:1999 (``ISO C99'').

HISTORY

     An assert macro appeared in Version 6 AT&T UNIX.

BSD
								 January 26, 1999							       BSD

assert.h(3HEAD) 						      Headers							   assert.h(3HEAD)

NAME

       assert.h, assert - verify program assertion

SYNOPSIS

       #include <assert.h>

DESCRIPTION

       The <assert.h> header defines 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 is defined simply as:

	 #define assert(ignore)((void) 0)

       Otherwise, the macro behaves as described in assert(3C).

       The assert() macro is redefined according to the current state of NDEBUG each time <assert.h> is included.

       The assert() macro is implemented as a macro, not as a function. If the macro definition is suppressed in order to access an  actual  func-
       tion, the behavior is undefined.

ATTRIBUTES

       See attributes(5) for descriptions of the following attributes:

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE TYPE	     |	    ATTRIBUTE VALUE	   |
       +-----------------------------+-----------------------------+
       |Interface Stability	     |Standard			   |
       +-----------------------------+-----------------------------+

SEE ALSO

       assert(3C), attributes(5), standards(5)

SunOS 5.11							    10 Sep 2004 						   assert.h(3HEAD)