assert(3X)                                                       assert(3X)

NAME
     assert - verify program assertion

SYNOPSIS
     #include <assert.h>

     void assert(int expression);

DESCRIPTION
     This macro is useful for putting diagnostics into programs. When it is
     executed, if expression returns the value zero, assert() prints the
     message:

          "Assertion failed: expression, file xyz, line nnn"

     on the standard error output and aborts. In the error message, xyz is
     the name of the source file and nnn the source line number of the
     assert statement. The latter are respectively the values of the
     preprocessor macros FILE and LINE.

     Compiling with the preprocessor control instruction #define NDEBUG
     ahead of the #include assert.h statement will stop assertions from
     being compiled into the program.

NOTES
     Since assert() is implemented as a macro, the expression may not con-
     tain any string literals.

SEE ALSO
     abort(3C).

























Page 1                       Reliant UNIX 5.44                Printed 11/98