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FEGETENV(3)           DragonFly Library Functions Manual           FEGETENV(3)


NAME

     fegetenv, feholdexcept, fesetenv, feupdateenv -- manage floating-point
     environment


SYNOPSIS

     #include <fenv.h>

     int
     fegetenv(fenv_t *envp);

     int
     feholdexcept(fenv_t *envp);

     int
     fesetenv(const fenv_t *envp);

     int
     feupdateenv(const fenv_t *envp);


DESCRIPTION

     These functions manage the floating-point environment -- status flags,
     rounding direction modes and exception masks -- as one entity.  The envp
     input argument is an object representing the floating-point environment.
     The macro FE_DFL_ENV represents the default floating-point environment --
     the one installed at program startup.

     The fegetenv() function stores the current floating-point environment in
     the object pointed to by envp.

     The feholdexcept() function saves the current floating-point environment
     in the object pointed to by envp, clears the floating-point status flags,
     and then installs a non-stop (continue on floating-point exceptions) mode
     for all floating-point exceptions.

     The fesetenv() function establishes the floating-point environment
     represented by the object pointed to by envp.  The argument envp shall
     point to an object set by a call to fegetenv() or feholdexcept(), or
     equal the macro FE_DFL_ENV.  Note that fesetenv() merely installs the
     state of the floating-point status flags represented through its
     argument, and does not raise these floating-point exceptions.

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


RETURN VALUES

     The fegetenv(), feholdexcept(), fesetenv(), and feupdateenv() functions
     return zero on success, and non-zero if an error occurred.


SEE ALSO

     feclearexcept(3), feenableexcept(3), fegetround(3)


STANDARDS

     The fegetenv(), feholdexcept(), fesetenv(), and feupdateenv() functions
     conform to ISO/IEC 9899:1999 (``ISO C99'').

     The return types for fegetenv(), fesetenv(), and feupdateenv() are int
     for alignment with ISO/IEC 9899:1999 (``ISO C99'') Defect Report #202.

DragonFly 4.1                    June 5, 2013                    DragonFly 4.1

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