assert(3X)           UNIX System V(Specialized Libraries)            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 is false (zero), assert prints

            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 option -DNDEBUG [see cc(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
      cc(1), abort(3C)

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
























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