1.\" Copyright (c) 1991, 1993 2.\" The Regents of the University of California. All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. 9.\" 2. Redistributions in binary form must reproduce the above copyright 10.\" notice, this list of conditions and the following disclaimer in the 11.\" documentation and/or other materials provided with the distribution. 12.\" 3. Neither the name of the University nor the names of its contributors 13.\" may be used to endorse or promote products derived from this software 14.\" without specific prior written permission. 15.\" 16.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 17.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 20.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26.\" SUCH DAMAGE. 27.\" 28.Dd May 17, 2026 29.Dt MEMORY 3 30.Os 31.Sh NAME 32.Nm aligned_alloc , 33.Nm alloca , 34.Nm calloc , 35.Nm free , 36.Nm free_sized , 37.Nm free_aligned_sized , 38.Nm malloc , 39.Nm posix_memalign , 40.Nm realloc , 41.Nm reallocf , 42.Nm valloc , 43.Nm mmap , 44.Nm munmap 45.Nd memory management functions 46.Sh LIBRARY 47.Lb libc 48.Sh SYNOPSIS 49.In stdlib.h 50.Ft void * 51.Fn aligned_alloc "size_t alignment" "size_t size" 52.Ft void * 53.Fn alloca "size_t size" 54.Ft void * 55.Fn calloc "size_t nelem" "size_t elsize" 56.Ft void 57.Fn free "void *ptr" 58.Ft void 59.Fn free_sized "void *ptr" "size_t size" 60.Ft void 61.Fn free_aligned_sized "void *ptr" "size_t alignment" "size_t size" 62.Ft void * 63.Fn malloc "size_t size" 64.Ft int 65.Fn posix_memalign "void **ptr" "size_t alignment" "size_t size" 66.Ft void * 67.Fn realloc "void *ptr" "size_t size" 68.Ft void * 69.Fn reallocf "void *ptr" "size_t size" 70.Ft void * 71.Fn valloc "size_t size" 72.In sys/types.h 73.In sys/mman.h 74.Ft void * 75.Fn mmap "void * addr" "size_t len" "int prot" "int flags" "int fd" "off_t offset" 76.Ft int 77.Fn munmap "void *addr" "size_t len" 78.Sh DESCRIPTION 79These functions allocate and free memory for the calling process. 80They are described in the 81individual manual pages. 82.Sh SEE ALSO 83.Xr mmap 2 , 84.Xr aligned_alloc 3 , 85.Xr alloca 3 , 86.Xr calloc 3 , 87.Xr free 3 , 88.Xr free_aligned_sized 3 , 89.Xr free_sized 3 , 90.Xr malloc 3 , 91.Xr posix_memalign 3 , 92.Xr realloc 3 , 93.Xr reallocf 3 , 94.Xr valloc 3 95.Sh STANDARDS 96The 97.Fn calloc , 98.Fn free , 99.Fn malloc , 100and 101.Fn realloc 102functions conform to 103.St -isoC . 104.Pp 105The 106.Fn mmap , 107.Fn munmap , 108and 109.Fn posix_memalign 110functions conform to 111.St -p1003.1-2001 . 112.Pp 113The 114.Fn free_sized 115and 116.Fn free_aligned_sized 117functions conform to 118.St -isoC-2023 . 119