Section: Linux Programmer's Manual (3)
Return to Main Contents
copysign, copysignf, copysignl - copy sign of a number
double copysign(double x, double y);
float copysignf(float x, float y);
long double copysignl(long double x, long double y);
Link with -lm.
Feature Test Macro Requirements for glibc (see
_SVID_SOURCE || _BSD_SOURCE || _XOPEN_SOURCE >= 600 || _ISOC99_SOURCE ||
_POSIX_C_SOURCE >= 200112L;
functions return a value whose absolute value matches
but whose sign bit matches that of
both return -42.0.
On success, these functions return a value whose magnitude is taken from
and whose sign is taken from
is a NaN,
a NaN with the sign bit of
No errors occur.
This function is defined in IEC 559 (and the appendix with
recommended functions in IEEE 754/IEEE 854).
On architectures where the floating-point formats are not IEEE 754 compliant,
functions may treat a negative zero as positive.
This page is part of release 3.54 of the Linux
A description of the project,
and information about reporting bugs,
can be found at
- RETURN VALUE
- CONFORMING TO
- SEE ALSO
This document was created by
using the manual pages.
Time: 17:26:40 GMT, January 19, 2018