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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-15 19:40:15 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-15 19:40:15 +0000 |
commit | 399644e47874bff147afb19c89228901ac39340e (patch) | |
tree | 1c4c0b733f4c16b5783b41bebb19194a9ef62ad1 /man3/copysign.3 | |
parent | Initial commit. (diff) | |
download | manpages-399644e47874bff147afb19c89228901ac39340e.tar.xz manpages-399644e47874bff147afb19c89228901ac39340e.zip |
Adding upstream version 6.05.01.upstream/6.05.01
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'man3/copysign.3')
-rw-r--r-- | man3/copysign.3 | 93 |
1 files changed, 93 insertions, 0 deletions
diff --git a/man3/copysign.3 b/man3/copysign.3 new file mode 100644 index 0000000..9bd7932 --- /dev/null +++ b/man3/copysign.3 @@ -0,0 +1,93 @@ +'\" t +.\" Copyright 1993 David Metcalfe (david@prism.demon.co.uk) +.\" +.\" SPDX-License-Identifier: Linux-man-pages-copyleft +.\" +.\" References consulted: +.\" Linux libc source code +.\" Lewine's _POSIX Programmer's Guide_ (O'Reilly & Associates, 1991) +.\" 386BSD man pages +.\" Modified 1993-07-24 by Rik Faith (faith@cs.unc.edu) +.\" Modified 2002-08-10 by Walter Harms (walter.harms@informatik.uni-oldenburg.de) +.TH copysign 3 2023-07-20 "Linux man-pages 6.05.01" +.SH NAME +copysign, copysignf, copysignl \- copy sign of a number +.SH LIBRARY +Math library +.RI ( libm ", " \-lm ) +.SH SYNOPSIS +.nf +.B #include <math.h> +.PP +.BI "double copysign(double " x ", double " y ); +.BI "float copysignf(float " x ", float " y ); +.BI "long double copysignl(long double " x ", long double " y ); +.fi +.PP +.RS -4 +Feature Test Macro Requirements for glibc (see +.BR feature_test_macros (7)): +.RE +.PP +.BR copysign (), +.BR copysignf (), +.BR copysignl (): +.nf + _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L + || /* Since glibc 2.19: */ _DEFAULT_SOURCE + || /* glibc <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE +.fi +.SH DESCRIPTION +These functions return a value whose absolute value matches that of +.IR x , +but whose sign bit matches that of +.IR y . +.PP +For example, +.I "copysign(42.0,\ \-1.0)" +and +.I "copysign(\-42.0, \-1.0)" +both return \-42.0. +.SH RETURN VALUE +On success, these functions return a value whose magnitude is taken from +.I x +and whose sign is taken from +.IR y . +.PP +If +.I x +is a NaN, +a NaN with the sign bit of +.I y +is returned. +.SH ERRORS +No errors occur. +.SH ATTRIBUTES +For an explanation of the terms used in this section, see +.BR attributes (7). +.TS +allbox; +lbx lb lb +l l l. +Interface Attribute Value +T{ +.na +.nh +.BR copysign (), +.BR copysignf (), +.BR copysignl () +T} Thread safety MT-Safe +.TE +.sp 1 +.SH VERSIONS +On architectures where the floating-point formats are not IEEE 754 compliant, +these functions may treat a negative zero as positive. +.SH STANDARDS +C11, POSIX.1-2008. +.PP +This function is defined in IEC 559 (and the appendix with +recommended functions in IEEE 754/IEEE 854). +.SH HISTORY +C99, POSIX.1-2001, 4.3BSD. +.SH SEE ALSO +.BR signbit (3) |