# assert(3)

    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.