PROLOG¶

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.

NAME¶

fetestexcept - test floating-point exception flags

SYNOPSIS¶

#include <fenv.h>

int fetestexcept(int excepts);

DESCRIPTION¶

The fetestexcept() function shall determine which of a specified subset of the floating-point exception flags are currently set. The excepts argument specifies the floating-point status flags to be queried.

RETURN VALUE¶

The fetestexcept() function shall return the value of the bitwise-inclusive OR of the floating-point exception macros corresponding to the currently set floating-point exceptions included in excepts.

ERRORS¶

No errors are defined.

The following sections are informative.

EXAMPLES¶

The following example calls function f() if an invalid exception is set, and then function g() if an overflow exception is set:

#include <fenv.h>
/* ... */
{


    #pragma STDC FENV_ACCESS ON


    int set_excepts;


    feclearexcept(FE_INVALID | FE_OVERFLOW);


    // maybe raise exceptions


    set_excepts = fetestexcept(FE_INVALID | FE_OVERFLOW);


    if (set_excepts & FE_INVALID) f();


    if (set_excepts & FE_OVERFLOW) g();


    /* ... */
}

APPLICATION USAGE¶

None.

RATIONALE¶

None.

FUTURE DIRECTIONS¶

None.

SEE ALSO¶

feclearexcept(), fegetexceptflag(), feraiseexcept(), the Base Definitions volume of IEEE Std 1003.1-2001, <fenv.h>

COPYRIGHT¶

Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of Electrical and Electronics Engineers, Inc and The Open Group. In the event of any discrepancy between this version 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 .