Synopsis
#include <math.h>
double ceil(double x);
Description

ceil computes the smallest integer value not less than x.

IEC 60559 math library behavior

ceil(±0) is ±0.
ceil(±∞) is ±∞.

Portability

ceil conforms to ISO/IEC 9899:1990 (C90) and ISO/IEC 9899:1999 (C99).