ceil

CEIL(3)                    Linux Programmer's Manual                   CEIL(3)



NAME
       ceil, ceilf, ceill - ceiling function: smallest integral value not less
       than argument

SYNOPSIS
       #include <math.h>

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

DESCRIPTION
       These functions round x up to the nearest integer.

RETURN VALUE
       The rounded integer value. If x is integral or infinite,  x  itself  is
       returned.

ERRORS
       No  errors other than EDOM and ERANGE can occur.  If x is NaN, then NaN
       is returned and errno may be set to EDOM.

NOTES
       SUSv2 and POSIX 1003.1-2001 contain text about  overflow  (which  might
       set  errno  to ERANGE, or raise an 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 max-
       imum value of the exponent is smaller than the number of mantissa bits.
       For  the IEEE-754 standard 32-bit and 64-bit floating point numbers the
       maximum value of the exponent is 128 (resp. 1024), and  the  number  of
       mantissa bits is 24 (resp. 53).)

CONFORMING TO
       The  ceil() function conforms to SVID 3, POSIX, BSD 4.3, ISO 9899.  The
       other functions are from C99.

SEE ALSO
       floor(3), lrint(3), nearbyint(3), rint(3), round(3), trunc(3)



                                  2001-05-31                           CEIL(3)