NAME | LIBRARY | SYNOPSIS | DESCRIPTION | RETURN VALUE | ERRORS | ATTRIBUTES | STANDARDS | HISTORY | SEE ALSO | COLOPHON |
|
|
lround(3) Library Functions Manual lround(3)
lround, lroundf, lroundl, llround, llroundf, llroundl - round to nearest integer
Math library (libm, -lm)
#include <math.h> long lround(double x); long lroundf(float x); long lroundl(long double x); long long llround(double x); long long llroundf(float x); long long llroundl(long double x); Feature Test Macro Requirements for glibc (see feature_test_macros(7)): All functions shown above: _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L
These functions round their argument to the nearest integer value, rounding halfway cases away from zero, regardless of the current rounding direction (see fenv(3)). Note that unlike the round(3) and ceil(3), functions, the return type of these functions differs from that of their arguments.
These functions return the rounded integer value. If x is a NaN or an infinity, or the rounded value is too large to be stored in a long (long long in the case of the ll* functions), then a domain error occurs, and the return value is unspecified.
See math_error(7) for information on how to determine whether an error has occurred when calling these functions. The following errors can occur: Domain error: x is a NaN or infinite, or the rounded value is too large An invalid floating-point exception (FE_INVALID) is raised. These functions do not set errno.
For an explanation of the terms used in this section, see attributes(7). ┌─────────────────────────────────────┬───────────────┬─────────┐ │ Interface │ Attribute │ Value │ ├─────────────────────────────────────┼───────────────┼─────────┤ │ lround(), lroundf(), lroundl(), │ Thread safety │ MT-Safe │ │ llround(), llroundf(), llroundl() │ │ │ └─────────────────────────────────────┴───────────────┴─────────┘
C11, POSIX.1-2008.
glibc 2.1. C99, POSIX.1-2001.
ceil(3), floor(3), lrint(3), nearbyint(3), rint(3), round(3)
This page is part of the man-pages (Linux kernel and C library
user-space interface documentation) project. Information about
the project can be found at
⟨https://www.kernel.org/doc/man-pages/⟩. If you have a bug report
for this manual page, see
⟨https://git.kernel.org/pub/scm/docs/man-pages/man-pages.git/tree/CONTRIBUTING⟩.
This page was obtained from the tarball man-pages-6.9.1.tar.gz
fetched from
⟨https://mirrors.edge.kernel.org/pub/linux/docs/man-pages/⟩ on
2024-06-26. If you discover any rendering problems in this HTML
version of the page, or you believe there is a better or more up-
to-date source for the page, or you have corrections or
improvements to the information in this COLOPHON (which is not
part of the original manual page), send a mail to
man-pages@man7.org
Linux man-pages 6.9.1 2024-05-02 lround(3)
Pages that refer to this page: lrint(3), round(3), roundup(3)