---
name: "memory"
section: "3"
platform: "freebsd"
package: "base"
version: "16.0-CURRENT-20261027-61c70dc16a79"
release: "FreeBSD 16.0-CURRENT (2026-10-27)"
platforms: ["freebsd", "macos"]
url: "https://new.carta.tech/memory"
---

# memory(3)

memory management functions

## NAME

**aligned\_alloc**, **alloca**, **calloc**, **free**, **free\_sized**, **free\_aligned\_sized**, **malloc**, **posix\_memalign**, **realloc**, **reallocf**, **valloc**, **mmap**, **munmap** – memory management functions

## LIBRARY

Standard C Library (libc, -lc)

## SYNOPSIS

**#include \<stdlib.h\>**

*void* *\**\

**aligned\_alloc**(*size\_t alignment*, *size\_t size*);

*void* *\**\

**alloca**(*size\_t size*);

*void* *\**\

**calloc**(*size\_t nelem*, *size\_t elsize*);

*void*\

**free**(*void \*ptr*);

*void*\

**free\_sized**(*void \*ptr*, *size\_t size*);

*void*\

**free\_aligned\_sized**(*void \*ptr*, *size\_t alignment*, *size\_t size*);

*void* *\**\

**malloc**(*size\_t size*);

*int*\

**posix\_memalign**(*void \*\*ptr*, *size\_t alignment*, *size\_t size*);

*void* *\**\

**realloc**(*void \*ptr*, *size\_t size*);

*void* *\**\

**reallocf**(*void \*ptr*, *size\_t size*);

*void* *\**\

**valloc**(*size\_t size*);

**#include \<sys/types.h\>**

**#include \<sys/mman.h\>**

*void* *\**\

**mmap**(*void \* addr*, *size\_t len*, *int prot*, *int flags*, *int fd*, *off\_t offset*);

*int*\

**munmap**(*void \*addr*, *size\_t len*);

## DESCRIPTION

These functions allocate and free memory for the calling process. They are described in the individual manual pages.

## SEE ALSO

[mmap(2)](/mmap/2.md), [aligned\_alloc(3)](/aligned_alloc/3.md), [alloca(3)](/alloca/3.md), [calloc(3)](/calloc/3.md), [free(3)](/free/3.md), [free\_aligned\_sized(3)](/free_aligned_sized/3.md), [free\_sized(3)](/free_sized/3.md), [malloc(3)](/malloc/3.md), [posix\_memalign(3)](/posix_memalign/3.md), [realloc(3)](/realloc/3.md), [reallocf(3)](/reallocf/3.md), [valloc(3)](/valloc/3.md)

## STANDARDS

The **calloc**(), **free**(), **malloc**(), and **realloc**() functions conform to ISO/IEC 9899:1990 (“ISO C90”).

The **mmap**(), **munmap**(), and **posix\_memalign**() functions conform to IEEE Std 1003.1-2001 (“POSIX.1”).

The **free\_sized**() and **free\_aligned\_sized**() functions conform to ISO/IEC 9899:2024 (“ISO C23”).