---
name: "creal"
section: "3"
platform: "linux"
package: "man-pages"
version: "6.19-1"
release: "Arch Linux 2026-11-01"
platforms: ["linux", "freebsd"]
url: "https://new.carta.tech/creal"
---

# creal(3)

get real part of a complex number

## NAME

creal, crealf, creall - get real part of a complex number

## LIBRARY

Math library (*libm*, *-lm*)

## SYNOPSIS

```
#include <complex.h>
```

**double creal(double complex** *z***);** **float crealf(float complex** *z***);** **long double creall(long double complex** *z***);**

## DESCRIPTION

These functions return the real part of the complex number *z*.

One has:

```
    z = creal(z) + I * cimag(z)
```

## ATTRIBUTES

For an explanation of the terms used in this section, see [**attributes**(7)](/attributes/7.md).

| | | |
| --- | --- | --- |
| **Interface** | **Attribute** | **Value** |
| **creal**(), **crealf**(), **creall**() | Thread safety | MT-Safe |

## VERSIONS

GCC supports also \_\_real\_\_. That is a GNU extension.

## STANDARDS

C11, POSIX.1-2008.

## HISTORY

glibc 2.1. C99, POSIX.1-2001.

## SEE ALSO

[**cabs**(3)](/cabs/3.md), [**cimag**(3)](/cimag/3.md), [**complex**(7)](/complex/7.md)