FETESTEXCEPT(3P)                                    POSIX Programmer's Manual                                   FETESTEXCEPT(3P)



PROLOG
       This  manual  page is part of the POSIX Programmer's Manual.  The Linux implementation of this interface may differ (con-
       sult the corresponding Linux manual page for details of Linux behavior), or the  interface  may  not  be  implemented  on
       Linux.

NAME
       fetestexcept - test floating-point exception flags

SYNOPSIS
       #include <fenv.h>

       int fetestexcept(int excepts);


DESCRIPTION
       The  fetestexcept()  function  shall determine which of a specified subset of the floating-point exception flags are cur-
       rently set. The excepts argument specifies the floating-point status flags to be queried.

RETURN VALUE
       The fetestexcept() function shall return the value of the bitwise-inclusive OR of  the  floating-point  exception  macros
       corresponding to the currently set floating-point exceptions included in excepts.

ERRORS
       No errors are defined.

       The following sections are informative.

EXAMPLES
       The  following  example calls function f() if an invalid exception is set, and then function g() if an overflow exception
       is set:


              #include <fenv.h>
              /* ... */
              {
                  #pragma STDC FENV_ACCESS ON
                  int set_excepts;
                  feclearexcept(FE_INVALID | FE_OVERFLOW);
                  // maybe raise exceptions
                  set_excepts = fetestexcept(FE_INVALID | FE_OVERFLOW);
                  if (set_excepts & FE_INVALID) f();
                  if (set_excepts & FE_OVERFLOW) g();
                  /* ... */
              }

APPLICATION USAGE
       None.

RATIONALE
       None.

FUTURE DIRECTIONS
       None.

SEE ALSO
       feclearexcept(), fegetexceptflag(), feraiseexcept(), the Base Definitions volume of IEEE Std 1003.1-2001, <fenv.h>

COPYRIGHT
       Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2003  Edition,  Standard  for
       Information  Technology -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 6, Copy-
       right (C) 2001-2003 by the Institute of Electrical and Electronics Engineers, Inc and The Open Group. In the event of any
       discrepancy  between this version and the original IEEE and The Open Group Standard, the original IEEE and The Open Group
       Standard  is  the  referee   document.   The   original   Standard   can   be   obtained   online   at   http://www.open-
       group.org/unix/online.html .



IEEE/The Open Group                                           2003                                              FETESTEXCEPT(3P)