# rintl(3p) [centos man page]

```RINT(3P)						     POSIX Programmer's Manual							  RINT(3P)

PROLOG
This  manual page is part of the POSIX Programmer's Manual.  The Linux implementation of this interface may differ (consult the correspond-
ing Linux manual page for details of Linux behavior), or the interface may not be implemented on Linux.

NAME
rint, rintf, rintl - round-to-nearest integral value

SYNOPSIS
#include <math.h>

double rint(double x);
float rintf(float x);
long double rintl(long double x);

DESCRIPTION
These functions shall return the integral value (represented as a double) nearest x in the direction of the current rounding mode. The cur-
rent rounding mode is implementation-defined.

If  the	current  rounding  mode  rounds toward negative infinity, then rint() shall be equivalent to floor(). If the current rounding mode
rounds toward positive infinity, then rint() shall be equivalent to ceil().

These functions differ from the nearbyint(), nearbyintf(), and nearbyintl() functions only in that they may  raise  the	inexact  floating-
point exception if the result differs in value from the argument.

An  application	wishing  to check for error situations should set errno to zero and call feclearexcept(FE_ALL_EXCEPT) before calling these
functions.  On return, if errno is non-zero or fetestexcept(FE_INVALID | FE_DIVBYZERO | FE_OVERFLOW | FE_UNDERFLOW) is non-zero,  an  error
has occurred.

RETURN VALUE
Upon  successful completion, these functions shall return the integer (represented as a double precision number) nearest x in the direction
of the current rounding mode.

If x is NaN, a NaN shall be returned.

If x is +-0 or +-Inf, x shall be returned.

If the correct value would cause overflow, a range error shall occur and rint(), rintf(), and rintl() shall return the value of	the  macro
+-HUGE_VAL, +-HUGE_VALF, and +-HUGE_VALL (with the same sign as x), respectively.

ERRORS
These functions shall fail if:

Range Error
The result would cause an overflow.

If  the	integer  expression  (math_errhandling	&  MATH_ERRNO) is non-zero, then errno shall be set to [ERANGE]. If the integer expression
(math_errhandling & MATH_ERREXCEPT) is non-zero, then the overflow floating-point exception shall be raised.

The following sections are informative.

EXAMPLES
None.

APPLICATION USAGE
On error, the expressions (math_errhandling & MATH_ERRNO) and (math_errhandling & MATH_ERREXCEPT) are independent of  each  other,  but	at
least one of them must be non-zero.

RATIONALE
None.

FUTURE DIRECTIONS
None.

abs(), ceil(), feclearexcept(), fetestexcept(), floor(), isnan(), nearbyint(), the Base Definitions volume of IEEE Std 1003.1-2001, Section
4.18, Treatment of Error Conditions for Mathematical Functions, <math.h>

Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2003 Edition, Standard for Information Technol-
ogy -- 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 .

IEEE/The Open Group						       2003								  RINT(3P)```

## Check Out this Related Man Page

```RINT(P) 						     POSIX Programmer's Manual							   RINT(P)

NAME
rint, rintf, rintl - round-to-nearest integral value

SYNOPSIS
#include <math.h>

double rint(double x);
float rintf(float x);
long double rintl(long double x);

DESCRIPTION
These functions shall return the integral value (represented as a double) nearest x in the direction of the current rounding mode. The cur-
rent rounding mode is implementation-defined.

If the current rounding mode rounds toward negative infinity, then rint() shall be equivalent to floor() . If  the  current  rounding  mode
rounds toward positive infinity, then rint() shall be equivalent to ceil() .

These  functions  differ  from  the nearbyint(), nearbyintf(), and nearbyintl() functions only in that they may raise the inexact floating-
point exception if the result differs in value from the argument.

An application wishing to check for error situations should set errno to zero and call feclearexcept(FE_ALL_EXCEPT)  before  calling  these
functions.   On	return, if errno is non-zero or fetestexcept(FE_INVALID | FE_DIVBYZERO | FE_OVERFLOW | FE_UNDERFLOW) is non-zero, an error
has occurred.

RETURN VALUE
Upon successful completion, these functions shall return the integer (represented as a double precision number) nearest x in the  direction
of the current rounding mode.

If x is NaN, a NaN shall be returned.

If x is +-0 or +-Inf, x shall be returned.

If  the	correct value would cause overflow, a range error shall occur and rint(), rintf(), and rintl() shall return the value of the macro
+-HUGE_VAL, +-HUGE_VALF, and +-HUGE_VALL (with the same sign as x), respectively.

ERRORS
These functions shall fail if:

Range Error
The result would cause an overflow.

If the integer expression (math_errhandling & MATH_ERRNO) is non-zero, then errno shall be set  to  [ERANGE].  If  the  integer	expression
(math_errhandling & MATH_ERREXCEPT) is non-zero, then the overflow floating-point exception shall be raised.

The following sections are informative.

EXAMPLES
None.

APPLICATION USAGE
On  error,  the	expressions  (math_errhandling & MATH_ERRNO) and (math_errhandling & MATH_ERREXCEPT) are independent of each other, but at
least one of them must be non-zero.

RATIONALE
None.

FUTURE DIRECTIONS
None.

abs() , ceil() , feclearexcept() , fetestexcept() , floor() , isnan() , nearbyint() , the Base Definitions volume of  IEEE Std 1003.1-2001,
Section 4.18, Treatment of Error Conditions for Mathematical Functions, <math.h>