projects / thirdparty / man-pages.git / blame
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1 | .\" Copyright (C) 2001 Andries Brouwer <aeb@cwi.nl>. |
| 2 | .\" | |
| 3 | .\" Permission is granted to make and distribute verbatim copies of this | |
| 4 | .\" manual provided the copyright notice and this permission notice are | |
| 5 | .\" preserved on all copies. | |
| 6 | .\" | |
| 7 | .\" Permission is granted to copy and distribute modified versions of this | |
| 8 | .\" manual under the conditions for verbatim copying, provided that the | |
| 9 | .\" entire resulting derived work is distributed under the terms of a | |
| 10 | .\" permission notice identical to this one. | |
| c13182ef | 11 | .\" |
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12 | .\" Since the Linux kernel and libraries are constantly changing, this |
| 13 | .\" manual page may be incorrect or out-of-date. The author(s) assume no | |
| 14 | .\" responsibility for errors or omissions, or for damages resulting from | |
| 15 | .\" the use of the information contained herein. The author(s) may not | |
| 16 | .\" have taken the same level of care in the production of this manual, | |
| 17 | .\" which is licensed free of charge, as they might when working | |
| 18 | .\" professionally. | |
| c13182ef | 19 | .\" |
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20 | .\" Formatted or processed versions of this manual, if unaccompanied by |
| 21 | .\" the source, must acknowledge the copyright and authors of this work. | |
| 22 | .\" | |
| f0d7ce1d | 23 | .TH TRUNC 3 2008-08-11 "" "Linux Programmer's Manual" |
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24 | .SH NAME |
| 25 | trunc, truncf, truncl \- round to integer, towards zero | |
| 26 | .SH SYNOPSIS | |
| 27 | .nf | |
| 28 | .B #include <math.h> | |
| 29 | .sp | |
| 30 | .BI "double trunc(double " x ); | |
| 31 | .br | |
| 32 | .BI "float truncf(float " x ); | |
| 33 | .br | |
| 34 | .BI "long double truncl(long double " x ); | |
| 35 | .fi | |
| 36 | .sp | |
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37 | Link with \fI\-lm\fP. |
| 38 | .sp | |
| 39 | .in -4n | |
| 40 | Feature Test Macro Requirements for glibc (see | |
| 41 | .BR feature_test_macros (7)): | |
| 42 | .in | |
| 43 | .sp | |
| 44 | .ad l | |
| 45 | .BR trunc (), | |
| 46 | .BR truncf (), | |
| 47 | .BR truncl (): | |
| 5161d9e0 | 48 | .RS 4 |
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49 | _XOPEN_SOURCE\ >=\ 600 || _ISOC99_SOURCE || |
| 50 | _POSIX_C_SOURCE\ >=\ 200112L; | |
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51 | .br |
| 52 | or | |
| cc4615cc | 53 | .I cc\ -std=c99 |
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54 | .RE |
| 55 | .ad | |
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56 | .SH DESCRIPTION |
| 57 | These functions round \fIx\fP to the nearest integer | |
| 58 | not larger in absolute value. | |
| 59 | .SH "RETURN VALUE" | |
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60 | These functions return the rounded integer value. |
| 61 | ||
| 62 | If \fIx\fP is integral, infinite, or NaN, \fIx\fP itself is returned. | |
| fea681da | 63 | .SH ERRORS |
| f1ab30a7 | 64 | No errors occur. |
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65 | .SH VERSIONS |
| 66 | These functions first appeared in glibc in version 2.1. | |
| fea681da | 67 | .SH "CONFORMING TO" |
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68 | C99, POSIX.1-2001. |
| 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. | |
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78 | .SH "SEE ALSO" |
| 79 | .BR ceil (3), | |
| 80 | .BR floor (3), | |
| 81 | .BR lrint (3), | |
| 82 | .BR nearbyint (3), | |
| 83 | .BR rint (3), | |
| 84 | .BR round (3) |