Sun Microsystems, Inc. gratefully acknowledges The Open Group for
permission to reproduce portions of its copyrighted documentation.
Original documentation from The Open Group can be obtained online at
http://www.opengroup.org/bookstore/.

The Institute of Electrical and Electronics Engineers and The Open
Group, have given us permission to reprint portions of their
documentation.

In the following statement, the phrase ``this text'' refers to portions
of the system documentation.

Portions of this text are reprinted and reproduced in electronic form
in the SunOS Reference Manual, from IEEE Std 1003.1, 2004 Edition,
Standard for Information Technology -- Portable Operating System
Interface (POSIX), The Open Group Base Specifications Issue 6,
Copyright (C) 2001-2004 by the Institute of Electrical and Electronics
Engineers, Inc and The Open Group. In the event of any discrepancy
between these versions 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.

This notice shall appear on any product containing this material.

The contents of this file are subject to the terms of the
Common Development and Distribution License (the "License").
You may not use this file except in compliance with the License.

You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
or http://www.opensolaris.org/os/licensing.
See the License for the specific language governing permissions
and limitations under the License.

When distributing Covered Code, include this CDDL HEADER in each
file and include the License file at usr/src/OPENSOLARIS.LICENSE.
If applicable, add the following below this CDDL HEADER, with the
fields enclosed by brackets "[]" replaced with your own identifying
information: Portions Copyright [yyyy] [name of copyright owner]


Copyright (c) 2001, The IEEE and The Open Group. All Rights Reserved.
Portions Copyright (c) 2006, Sun Microsystems, Inc. All Rights Reserved.

FEGETENV 3M "Jul 12, 2006" "SunOS 5.11" "Mathematical Library Functions"
NAME
fegetenv, fesetenv - get and set current floating-point environment
SYNOPSIS

c99 [ flag... ] file... -lm [ library... ]
#include <fenv.h>

int fegetenv(fenv_t *envp);

int fesetenv(const fenv_t *envp);
DESCRIPTION

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

The fesetenv() function attempts to establish the floating-point environment represented by the object pointed to by envp. The envp argument points to an object set by a call to fegetenv() or feholdexcept(3M), or equals 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 VALUES

If the representation was successfully stored, fegetenv returns 0. Otherwise, it returns a non-zero value.

If the environment was successfully established, fesetenv returns 0. Otherwise, it returns a non-zero value.

ERRORS

No errors are defined.

ATTRIBUTES

See attributes(5) for descriptions of the following attributes:

ATTRIBUTE TYPE ATTRIBUTE VALUE
Interface Stability Standard
MT-Level MT-Safe
SEE ALSO

feholdexcept(3M), fenv.h(3HEAD), feupdateenv(3M), attributes(5), standards(5)

NOTES

In a multithreaded program, the fegetenv() and fegetenv() functions affect the floating point environment only for the calling thread.

These functions automatically install and deinstall SIGFPE handlers and set and clear the trap enable mode bits in the floating point status register as needed. If a program uses these functions and attempts to install a SIGFPE handler or control the trap enable mode bits independently, the resulting behavior is not defined.

As described in fex_set_handling(3M), when a handling function installed in FEX_CUSTOM mode is invoked, all exception traps are disabled (and will not be reenabled while SIGFPE is blocked). Thus, attempting to change the environment from within a handler by calling fesetenv or feupdateenv(3M) might not produce the expected results.