NAME

     assert - program verification


SYNOPSIS

     #include <assert.h>

     void assert(int expression)


DESCRIPTION

     Assert is a macro that indicates expression is  expected  to
     be true at this point in the program.  It causes an abort(3)
     with a  diagnostic  comment  on  the  standard  output  when
     expression  is  false  (0).  Compiling with the cc(1) option
     -DNDEBUG effectively deletes assert from the program.


DIAGNOSTICS

     `Assertion "expression" failed: file f line n.'   F  is  the
     source  file  and  n  the  source  line number of the assert
     statement.