fegetenv - Man Page

get and set current 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.


#include <fenv.h>

int fegetenv(fenv_t *envp);
int fesetenv(const fenv_t *envp);


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 fegetenv() function shall attempt to store the current floating-point environment in the object pointed to by envp.

The fesetenv() function shall attempt to establish 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 a floating-point environment macro. The fesetenv() function does not raise floating-point exceptions, but only installs the state of the floating-point status flags represented through its argument.

Return Value

If the representation was successfully stored, fegetenv() shall return zero. Otherwise, it shall return a non-zero value. If the environment was successfully established, fesetenv() shall return zero. Otherwise, it shall return a non-zero value.


No errors are defined.

The following sections are informative.



Application Usage




Future Directions


See Also

feholdexcept(), feupdateenv()

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

Referenced By

feholdexcept(3p), fenv.h(0p), feupdateenv(3p).

2017 IEEE/The Open Group POSIX Programmer's Manual