HP-UX Reference (11i v1 05/09) - 3 Library Functions A-M (vol 6)

f
feholdexcept(3M) feholdexcept(3M)
NAME
feholdexcept( ) - save floating-point environment
SYNOPSIS
#include <fenv.h>
int feholdexcept(fenv_t *envp);
DESCRIPTION
The feholdexcept()
function saves the current floating-point environment in the object pointed to by
the argument envp, clears the exception flags, and disables all traps.
Use
feholdexcept()
with feupdateenv()
to hide spurious exceptions. Use it with fesetenv()
to hide all exceptions.
The ISO/ANSI C committee has approved the
feholdexcept()
function for inclusion in the C9X draft
standard.
To use this function, compile either with the default
-Ae option or with the -Aa and -D_HPUX_SOURCE
options. Make sure your program includes <fenv.h>. Link in the math library by specifying -lm
on the
compiler or linker command line.
For more information, see the HP-UX Floating-Point Guide.
RETURN VALUE
The
feholdexcept() function returns a zero value, indicating the successful disabling of any traps.
ERRORS
No errors are defined.
EXAMPLE
Store the current floating-point environment in
holdenv, hide spurious underflow exceptions, and con-
tinue on any exceptions that occur until the call to feupdateenv()
is encountered.
#include <fenv.h>
/*...*/
fenv_t holdenv;
feholdexcept(&holdenv);
/* perform operations */
if (/* test for spurious underflow */)
feclearexcept(FE_UNDERFLOW);
feupdateenv(&holdenv); /* raise accumulated exceptions */
SEE ALSO
fegetenv(3M), fesetenv(3M), feupdateenv(3M), fenv(5).
Section 3−−248 Hewlett-Packard Company − 1 − HP-UX 11i Version 1: September 2005