**ceill**

SYNOPSIS
#include <math.h>
double ceil(double x);
float ceilf(float x);
long double ceill(long double x);
Link with -lm.
Feature Test Macro Requirements for glibc (see **feature_test_macros(7)**):
ceilf(), ceill():
_BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE >= 600 ||
_ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L;
or cc -std=c99
DESCRIPTION
These functions return the smallest integral value that is not less
than x.
For example, ceil(0.5) is 1.0, and ceil(-0.5) is 0.0.
RETURN VALUE
These functions return the ceiling of x.
If x is integral, +0, -0, NaN, or infinite, x itself is returned.
ERRORS
No errors occur. POSIX.1-2001 documents a range error for overflows,
but see NOTES.
ATTRIBUTES
For an explanation of the terms used in this section, see
**attributes(7)**.
+-------------------------+---------------+---------+
|Interface | Attribute | Value |
+-------------------------+---------------+---------+
|ceil(), ceilf(), ceill() | Thread safety | MT-Safe |
+-------------------------+---------------+---------+
CONFORMING TO
C99, POSIX.1-2001, POSIX.1-2008.
The variant returning double also conforms to SVr4, 4.3BSD, C89.
NOTES
SUSv2 and POSIX.1-2001 contain text about overflow (which might set
errno to ERANGE, or raise an FE_OVERFLOW exception). In practice, the
result cannot overflow on any current machine, so this error-handling
stuff is just nonsense. (More precisely, overflow can happen only when
the maximum value of the exponent is smaller than the number of man-
tissa bits. For the IEEE-754 standard 32-bit and 64-bit floating-point
numbers the maximum value of the exponent is 128 (respectively, 1024),
and the number of mantissa bits is 24 (respectively, 53).)
description of the project, information about reporting bugs, and the
latest version of this page, can be found at
http://www.kernel.org/doc/man-pages/.
2015-04-19 **CEIL(3)**

###### Man Pages Copyright Respective Owners. Site Copyright (C) 1994 - 2019
Hurricane Electric.
All Rights Reserved.