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man pages section 3: Extended Library Functions, Volume 2

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Updated: Thursday, June 13, 2019
 
 

feholdexcept(3M)

Name

feholdexcept - save current floating-point environment

Synopsis

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

int feholdexcept(fenv_t *envp);

Description

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, if available, for all floating-point exceptions.

Return Values

The feholdexcept() function returns 0 if and only if non-stop floating-point exception handling was successfully installed.

Errors

No errors are defined.

Attributes

See attributes(7) for descriptions of the following attributes:

ATTRIBUTE TYPE
ATTRIBUTE VALUE
Interface Stability
Committed
Availability
system/library/math
MT-Level
MT-Safe
Standard

See Also

fenv.h(3HEAD), fegetenv(3M), feupdateenv(3M), attributes(7), standards(7)

Notes

In a multithreaded program, the feholdexcept() function affects the floating point environment only for the calling thread.

The feholdexcept() function automatically installs and deinstalls SIGFPE handlers and sets and clears 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.