1fegetenv(3M)            Mathematical Library Functions            fegetenv(3M)
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NAME

6       fegetenv, fesetenv - get and set current floating-point environment
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SYNOPSIS

9       c99 [ flag... ] file... -lm [ library... ]
10       #include <fenv.h>
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12       int fegetenv(fenv_t *envp);
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15       int fesetenv(const fenv_t *envp);
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DESCRIPTION

19       The  fegetenv()  function  attempts to store the current floating-point
20       environment in the object pointed to by envp.
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23       The fesetenv() function attempts to establish the floating-point  envi‐
24       ronment represented by the object pointed to by envp. The envp argument
25       points to an object set by a call to fegetenv() or feholdexcept(3M), or
26       equals a floating-point environment macro. The fesetenv() function does
27       not raise floating-point exceptions, but only installs the state of the
28       floating-point status flags represented through its argument.
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RETURN VALUES

31       If the representation was successfully stored, fegetenv returns 0. Oth‐
32       erwise, it returns a non-zero value.
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35       If the environment was successfully established,  fesetenv  returns  0.
36       Otherwise, it returns a non-zero value.
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ERRORS

39       No errors are defined.
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ATTRIBUTES

42       See attributes(5) for descriptions of the following attributes:
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47       ┌─────────────────────────────┬─────────────────────────────┐
48       │      ATTRIBUTE TYPE         │      ATTRIBUTE VALUE        │
49       ├─────────────────────────────┼─────────────────────────────┤
50       │Interface Stability          │Standard                     │
51       ├─────────────────────────────┼─────────────────────────────┤
52       │MT-Level                     │MT-Safe                      │
53       └─────────────────────────────┴─────────────────────────────┘
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SEE ALSO

56       feholdexcept(3M),  fenv.h(3HEAD), feupdateenv(3M), attributes(5), stan‐
57       dards(5)
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NOTES

60       In a multithreaded program, the  fegetenv()  and  fegetenv()  functions
61       affect the floating point environment only for the calling thread.
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64       These functions automatically install and deinstall SIGFPE handlers and
65       set and clear the trap enable mode bits in the  floating  point  status
66       register  as  needed. If a program uses these functions and attempts to
67       install a SIGFPE handler or control the trap enable mode bits  indepen‐
68       dently, the resulting behavior is not defined.
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71       As   described   in  fex_set_handling(3M),  when  a  handling  function
72       installed in FEX_CUSTOM mode is invoked, all exception traps  are  dis‐
73       abled  (and  will  not  be  reenabled  while  SIGFPE is blocked). Thus,
74       attempting to change the environment from within a handler  by  calling
75       fesetenv or feupdateenv(3M) might not produce the expected results.
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79SunOS 5.11                        12 Jul 2006                     fegetenv(3M)
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