ceil, ceilf, ceill
Header: <math.h>
1-3) Computes the smallest integer value not less than arg.
# Declarations
float ceilf( float arg );
(since C99)
double ceil( double arg );
long double ceill( long double arg );
(since C99)
#define ceil( arg )
(since C99)
# Parameters
arg: floating-point value
# Return value
If no errors occur, the smallest integer value not less than arg, that is ⌈arg⌉, is returned.
# Notes
FE_INEXACT may be (but isn’t required to be) raised when rounding a non-integer finite value.
The largest representable floating-point values are exact integers in all standard floating-point formats, so this function never overflows on its own; however the result may overflow any integer type (including intmax_t), when stored in an integer variable.
This function (for double argument) behaves as if (except for the freedom to not raise FE_INEXACT) implemented by
# Example
#include <math.h>
#include <stdio.h>
int main(void)
{
printf("ceil(+2.4) = %+.1f\n", ceil(2.4));
printf("ceil(-2.4) = %+.1f\n", ceil(-2.4));
printf("ceil(-0.0) = %+.1f\n", ceil(-0.0));
printf("ceil(-Inf) = %+f\n", ceil(-INFINITY));
}