projects / thirdparty / man-pages.git / blame
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1 | .\" Copyright (C) 2001 Andries Brouwer <aeb@cwi.nl>. |
| 2 | .\" | |
| 5fbde956 | 3 | .\" SPDX-License-Identifier: Linux-man-pages-copyleft |
| fea681da | 4 | .\" |
| 1ae6b2c7 | 5 | .TH TRUNC 3 2021-03-22 GNU "Linux Programmer's Manual" |
| fea681da | 6 | .SH NAME |
| 5fab2e7c | 7 | trunc, truncf, truncl \- round to integer, toward zero |
| dacc8b97 AC |
8 | .SH LIBRARY |
| 9 | Math library | |
| 8fc3b2cf | 10 | .RI ( libm ", " \-lm ) |
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11 | .SH SYNOPSIS |
| 12 | .nf | |
| 13 | .B #include <math.h> | |
| 68e4db0a | 14 | .PP |
| fea681da | 15 | .BI "double trunc(double " x ); |
| fea681da | 16 | .BI "float truncf(float " x ); |
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17 | .BI "long double truncl(long double " x ); |
| 18 | .fi | |
| 68e4db0a | 19 | .PP |
| d39ad78f | 20 | .RS -4 |
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21 | Feature Test Macro Requirements for glibc (see |
| 22 | .BR feature_test_macros (7)): | |
| d39ad78f | 23 | .RE |
| 68e4db0a | 24 | .PP |
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25 | .BR trunc (), |
| 26 | .BR truncf (), | |
| 27 | .BR truncl (): | |
| 9d2adbae | 28 | .nf |
| 5c10d2c5 | 29 | _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L |
| 9d2adbae | 30 | .fi |
| fea681da | 31 | .SH DESCRIPTION |
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32 | These functions round |
| 33 | .I x | |
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34 | to the nearest integer value that is not larger in magnitude than |
| 35 | .IR x . | |
| 47297adb | 36 | .SH RETURN VALUE |
| 35646edb | 37 | These functions return the rounded integer value, in floating format. |
| 847e0d88 | 38 | .PP |
| 022671eb | 39 | If |
| d8a86e74 | 40 | .I x |
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41 | is integral, infinite, or NaN, |
| 42 | .I x | |
| 43 | itself is returned. | |
| fea681da | 44 | .SH ERRORS |
| f1ab30a7 | 45 | No errors occur. |
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46 | .SH VERSIONS |
| 47 | These functions first appeared in glibc in version 2.1. | |
| d265b8f2 | 48 | .SH ATTRIBUTES |
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49 | For an explanation of the terms used in this section, see |
| 50 | .BR attributes (7). | |
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51 | .ad l |
| 52 | .nh | |
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53 | .TS |
| 54 | allbox; | |
| c466875e | 55 | lbx lb lb |
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56 | l l l. |
| 57 | Interface Attribute Value | |
| 58 | T{ | |
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59 | .BR trunc (), |
| 60 | .BR truncf (), | |
| d265b8f2 | 61 | .BR truncl () |
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62 | T} Thread safety MT-Safe |
| 63 | .TE | |
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64 | .hy |
| 65 | .ad | |
| 66 | .sp 1 | |
| 47297adb | 67 | .SH CONFORMING TO |
| 9a74e018 | 68 | C99, POSIX.1-2001, POSIX.1-2008. |
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69 | .SH NOTES |
| 70 | The integral value returned by these functions may be too large | |
| 71 | to store in an integer type | |
| 72 | .RI ( int , | |
| 73 | .IR long , | |
| 74 | etc.). | |
| 75 | To avoid an overflow, which will produce undefined results, | |
| 76 | an application should perform a range check on the returned value | |
| 77 | before assigning it to an integer type. | |
| 47297adb | 78 | .SH SEE ALSO |
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79 | .BR ceil (3), |
| 80 | .BR floor (3), | |
| 81 | .BR lrint (3), | |
| 82 | .BR nearbyint (3), | |
| 83 | .BR rint (3), | |
| 84 | .BR round (3) |