trunc(3)		    Library Functions Manual			trunc(3)

NAME
     trunc, truncf, truncl - round to integer, toward zero

LIBRARY
     Math library (libm, -lm)

SYNOPSIS
     #include <math.h>

     double trunc(double x);
     float truncf(float x);
     long double truncl(long double x);

 Feature Test Macro Requirements for glibc (see feature_test_macros(7)):

     trunc(), truncf(), truncl():
	 _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L

DESCRIPTION
     These  functions round x to the nearest integer value that is not larger in
     magnitude than x.

RETURN VALUE
     These functions return the rounded integer value, in floating format.

     If x is integral, infinite, or NaN, x itself is returned.

ERRORS
     No errors occur.

ATTRIBUTES
     For an explanation of the terms used in this  section,  see  attributes(7).
     allbox; lbx lb lb l l l.  Interface Attribute Value T{ trunc(), truncf(),
     truncl() T}   Thread safety  MT-Safe

STANDARDS
     C11, POSIX.1-2008.

HISTORY
     glibc 2.1.	 C99, POSIX.1-2001.

NOTES
     The integral value returned by these functions may be too large to store in
     an	 integer  type (int, long, etc.).  To avoid an overflow, which will pro-
     duce undefined results, an application should perform a range check on  the
     returned value before assigning it to an integer type.

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

Linux man-pages 6.18		   2026-02-08				trunc(3)