| .\" Copyright (C) 2001 Andries Brouwer <aeb@cwi.nl>. |
| .\" |
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| .TH TRUNC 3 2021-03-22 "" "Linux Programmer's Manual" |
| .SH NAME |
| trunc, truncf, truncl \- round to integer, toward zero |
| .SH SYNOPSIS |
| .nf |
| .B #include <math.h> |
| .PP |
| .BI "double trunc(double " x ); |
| .BI "float truncf(float " x ); |
| .BI "long double truncl(long double " x ); |
| .fi |
| .PP |
| Link with \fI\-lm\fP. |
| .PP |
| .RS -4 |
| Feature Test Macro Requirements for glibc (see |
| .BR feature_test_macros (7)): |
| .RE |
| .PP |
| .BR trunc (), |
| .BR truncf (), |
| .BR truncl (): |
| .nf |
| _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L |
| .fi |
| .SH DESCRIPTION |
| These functions round |
| .I x |
| to the nearest integer value that is not larger in magnitude than |
| .IR x . |
| .SH RETURN VALUE |
| These functions return the rounded integer value, in floating format. |
| .PP |
| If |
| .I x |
| is integral, infinite, or NaN, |
| .I x |
| itself is returned. |
| .SH ERRORS |
| No errors occur. |
| .SH VERSIONS |
| These functions first appeared in glibc in version 2.1. |
| .SH ATTRIBUTES |
| For an explanation of the terms used in this section, see |
| .BR attributes (7). |
| .ad l |
| .nh |
| .TS |
| allbox; |
| lbx lb lb |
| l l l. |
| Interface Attribute Value |
| T{ |
| .BR trunc (), |
| .BR truncf (), |
| .BR truncl () |
| T} Thread safety MT-Safe |
| .TE |
| .hy |
| .ad |
| .sp 1 |
| .SH CONFORMING TO |
| C99, POSIX.1-2001, POSIX.1-2008. |
| .SH NOTES |
| The integral value returned by these functions may be too large |
| to store in an integer type |
| .RI ( int , |
| .IR long , |
| etc.). |
| To avoid an overflow, which will produce undefined results, |
| an application should perform a range check on the returned value |
| before assigning it to an integer type. |
| .SH SEE ALSO |
| .BR ceil (3), |
| .BR floor (3), |
| .BR lrint (3), |
| .BR nearbyint (3), |
| .BR rint (3), |
| .BR round (3) |
