bionic (3) fetestexcept.3posix.gz

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PROLOG
       This  manual  page  is part of the POSIX Programmer's Manual.  The Linux implementation of this interface
       may differ (consult 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  functionality  described  on  this  reference  page is aligned with the ISO C standard. Any conflict
       between the requirements described  here  and  the  ISO C  standard  is  unintentional.  This  volume  of
       POSIX.1‐2008 defers to the ISO C standard.

       The  fetestexcept()  function shall determine which of a specified subset of the floating-point exception
       flags are currently 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 POSIX.1‐2008, <fenv.h>


       Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2013 Edition,
       Standard  for  Information Technology -- Portable Operating System Interface (POSIX), The Open Group Base
       Specifications Issue 7, Copyright (C) 2013 by the Institute of Electrical and Electronics Engineers,  Inc
       and  The  Open Group.  (This is POSIX.1-2008 with the 2013 Technical Corrigendum 1 applied.) 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.unix.org/online.html .

       Any typographical or formatting errors that appear in this page are most likely to have  been  introduced
       during   the   conversion  of  the  source  files  to  man  page  format.  To  report  such  errors,  see
       https://www.kernel.org/doc/man-pages/reporting_bugs.html .