linux man page for assert

ASSERT(3)						     Linux Programmer's Manual							 ASSERT(3)

NAME
       assert - abort the program if assertion is false

SYNOPSIS
       #include <assert.h>

       void assert(scalar expression);

DESCRIPTION
       If the macro NDEBUG was defined at the moment <assert.h> was last included, the macro assert() generates no code, and hence does nothing at
       all.  Otherwise, the macro assert() prints an error message to standard error and terminates the program by calling abort(3) if	expression
       is false (i.e., compares equal to zero).

       The  purpose  of  this  macro  is  to  help the programmer find bugs in his program.  The message "assertion failed in file foo.c, function
       do_bar(), line 1287" is of no help at all to a user.

RETURN VALUE
       No value is returned.

CONFORMING TO
       POSIX.1-2001, C89, C99.	In C89, expression is required to be of type int and undefined behavior results if it is not, but in  C99  it  may
       have any scalar type.

BUGS
       assert() is implemented as a macro; if the expression tested has side-effects, program behavior will be different depending on whether NDE-
       BUG is defined.	This may create Heisenbugs which go away when debugging is turned on.

SEE ALSO
       abort(3), assert_perror(3), exit(3)

COLOPHON
       This page is part of release 3.27 of the Linux man-pages project.  A description of the project, and information about reporting bugs,  can
       be found at http://www.kernel.org/doc/man-pages/.

GNU
								    2002-08-25								 ASSERT(3)