ASSERT(3X)           INTERACTIVE UNIX System           ASSERT(3X)



          NAME
               assert - verify program assertion

          SYNOPSIS
               #include <assert.h>

               assert (expression)
               int expression;

          DESCRIPTION
               This macro is useful for putting diagnostics into programs.
               When it is executed, if expression is false (zero), assert
               prints

                    ``Assertion failed: expression, file xyz, line nnn''

               on the standard error output and aborts.  In the error mes-
               sage, xyz is the name of the source file and nnn the source
               line number of the assert statement.

               Compiling with the preprocessor option -DNDEBUG [see
               cpp(1)], or with the preprocessor control statement
               ``#define NDEBUG'' ahead of the ``#include <assert.h>''
               statement, will stop assertions from being compiled into the
               program.

          SEE ALSO
               cpp(1), abort(3C).

          CAVEAT
               Since assert is implemented as a macro, the expression may
               not contain any string literals.























          Rev. C Software Development Set                            Page 1