# ceilf(3m) [opensolaris man page]

```ceil(3M)						  Mathematical Library Functions						  ceil(3M)

NAME
ceil, ceilf, ceill - ceiling value function

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

double ceil(double x);

float ceilf(float x);

long double ceill(long double x);

DESCRIPTION
These functions compute the smallest integral value not less than x.

RETURN VALUES
Upon  successful  completion, the ceil(), ceilf(), and ceill() functions return the smallest integral value not less than x, expressed as a
type double, float, or long double, respectively.

If x is NaN, a NaN is returned.

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

USAGE
The integral value returned by these functions need not be expressible as an int or long int. The return  value	should	be  tested  before
assigning it to an integer type to avoid the undefined results of an integer overflow.

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

+-----------------------------+-----------------------------+
|      ATTRIBUTE TYPE	     |	    ATTRIBUTE VALUE	   |
+-----------------------------+-----------------------------+
|Interface Stability	     |Standard			   |
+-----------------------------+-----------------------------+
|MT-Level		     |MT-Safe			   |
+-----------------------------+-----------------------------+

feclearexcept(3M), fetestexcept(3M), floor(3M), isnan(3M), math.h(3HEAD), attributes(5), standards(5)

SunOS 5.11							    12 Jul 2006 							  ceil(3M)```

## Check Out this Related Man Page

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

NAME
ceil, ceilf, ceill - ceiling value function

SYNOPSIS
#include <math.h>

double ceil(double x);
float ceilf(float x);
long double ceill(long double x);

DESCRIPTION
These functions shall compute the smallest integral value not less than x.

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, ceil(), ceilf(), and ceill() shall return the smallest integral value not less than x, expressed as a type dou-
ble, float, or long double, respectively.

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 ceil(), ceilf(), and ceill() shall return the value of	the  macro
HUGE_VAL, HUGE_VALF, and HUGE_VALL, respectively.

ERRORS
These functions shall fail if:

Range Error
The result overflows.

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
The integral value returned by these functions need not be expressible as an int or long. The return value should be tested before  assign-
ing it to an integer type to avoid the undefined results of an integer overflow.

The ceil() function can only overflow when the floating-point representation has DBL_MANT_DIG > DBL_MAX_EXP.

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.