COPYSIGN(3) | Library Functions Manual | COPYSIGN(3)

# NAME

`copysign`, `copysignf`, `copysignl` — copy sign

# SYNOPSIS

Math Library (libm, -lm)
`#include <math.h>`

double
`copysign`(double x, double y);

float
`copysignf`(float x, float y);

long double
`copysignl`(long double x, long double y);

# DESCRIPTION

`copysign`() returns x with its sign changed to y's. The `copysignf`() function is a single precision version of `copysign`(). The `copysignl`() function is an extended precision version of `copysign`().

# SEE ALSO

fabs(3)

# STANDARDS

IEEE Std 754-1985

# HISTORY

The `copysign`, `copysignf` and `copysignl` functions appeared in 4.3BSD, NetBSD 1.1 and OpenBSD 4.5, respectively.

June 7, 2025 | Debian