usr/share/man/cat3/rint.0

RINT(3)                     BSD Programmer's Manual                    RINT(3)

N\bNA\bAM\bME\bE
     r\bri\bin\bnt\bt - and round-to-closest integer functions

S\bSY\bYN\bNO\bOP\bPS\bSI\bIS\bS
     #\b#i\bin\bnc\bcl\blu\bud\bde\be <\b<m\bma\bat\bth\bh.\b.h\bh>\b>

     _\bd_\bo_\bu_\bb_\bl_\be
     r\bri\bin\bnt\bt(_\bd_\bo_\bu_\bb_\bl_\be _\bx);

D\bDE\bES\bSC\bCR\bRI\bIP\bPT\bTI\bIO\bON\bN
     The r\bri\bin\bnt\bt() function finds the integer (represented as a double precision
     number) nearest to _\bx in the direction of the prevailing rounding mode.

N\bNO\bOT\bTE\bES\bS
     On a VAX, r\bri\bin\bnt\bt(_\bx) is equivalent to adding half to the magnitude and then
     rounding towards zero.

     In the default rounding mode, to nearest, on a machine that conforms to
     IEEE 754, r\bri\bin\bnt\bt(_\bx) is the integer nearest _\bx with the additional stipula-
     tion that if |rint(x)-x|=1/2 then r\bri\bin\bnt\bt(_\bx) is even.  Other rounding modes
     can make r\bri\bin\bnt\bt() act like f\bfl\blo\boo\bor\br(), or like c\bce\bei\bil\bl(), or round towards zero.

     Another way to obtain an integer near _\bx is to declare (in C)

           double x;     int k;    k = x;

     Most C compilers round _\bx towards 0 to get the integer _\bk, but some do oth-
     erwise.  If in doubt, use f\bfl\blo\boo\bor\br(), c\bce\bei\bil\bl(), or r\bri\bin\bnt\bt() first, whichever you
     intend.  Also note that, if x is larger than _\bk can accommodate, the value
     of _\bk and the presence or absence of an integer overflow are hard to pre-
     dict.

S\bSE\bEE\bE A\bAL\bLS\bSO\bO
     abs(3),  fabs(3),  ceil(3),  floor(3),  ieee(3),  math(3)

H\bHI\bIS\bST\bTO\bOR\bRY\bY
     A r\bri\bin\bnt\bt() function appeared in Version 6 AT&T UNIX.

4.4BSD                           June 4, 1993                                1