fetestexcept

- test floating-point exception flags

Synopsis

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

int fetestexcept(int excepts);

Description

The fetestexcept() function determines 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 Values

The fetestexcept() function returns 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.

Examples

Example 1 Example using fetestexcept()

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();
      /* ... */
}

Attributes

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

See Also

feclearexcept(3M), fegetexceptflag(3M), fenv.h(3HEAD), attributes(5), standards(5)