This manual page is part of the POSIX Programmer's Manual. The Linux implementation of this interface

       None.

       Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1-2017, Standard
       for Information  Technology  --  Portable  Operating  System  Interface  (POSIX),  The  Open  Group  Base
       Specifications  Issue  7, 2018 Edition, Copyright (C) 2018 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.opengroup.org/unix/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 .

IEEE/The Open Group                                   2017                                   FEUPDATEENV(3POSIX)

       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.1‐2017 defers to the ISO C standard.

       The  feupdateenv()  function  shall attempt to save the currently raised floating-point exceptions in its
       automatic storage, attempt to install the floating-point environment represented by the object pointed to
       by envp, and then attempt to raise the saved floating-point exceptions. The argument envp shall point  to
       an object set by a call to feholdexcept() or fegetenv(), or equal a floating-point environment macro.

       No errors are defined.

       Thefollowingsectionsareinformative.

       The following example shows sample code to hide spurious underflow floating-point exceptions:

           #include <fenv.h>
           double f(double x)
           {
               #pragma STDC FENV_ACCESS ON
               double result;
               fenv_t save_env;
               feholdexcept(&save_env);
               // compute result
               if (/* test spurious underflow */)
               feclearexcept(FE_UNDERFLOW);
               feupdateenv(&save_env);
               return result;
           }

       None.

       feupdateenv — update floating-point environment

       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.

       None.

       The  feupdateenv()  function  shall  return  a  zero  value  if and only if all the required actions were
       successfully carried out.

fegetenv(), feholdexcept()

       The Base Definitions volume of POSIX.1‐2017, <fenv.h>

       #include <fenv.h>

       int feupdateenv(const fenv_t *envp);