CEIL(3) Linux Programmer's Manual CEIL(3)
ceil - smallest integral value not less than x
#include <math.h> double ceil (double x);
The ceil() function rounds x upwards to the nearest inte- ger, returning that value as a double.
SVID 3, POSIX, BSD 4.3, ISO 9899
abs(3), fabs(3), floor(3), labs(3), rint(3) June 6, 1993 1