'\" t
.\" Copyright, the authors of the Linux man-pages project
.\"
.\" SPDX-License-Identifier: Linux-man-pages-copyleft
.\"
.TH memalign 3 2025-12-13 "Linux man-pages 6.18"
.SH NAME
memalign
\-
allocate aligned memory
.SH LIBRARY
Standard C library
.RI ( libc ,\~ \-lc )
.SH SYNOPSIS
.nf
.B #include <malloc.h>
.P
.BI "[[deprecated]] void *memalign(size_t " alignment ", size_t " size );
.fi
.SH DESCRIPTION
.BR memalign ()
is equivalent to
.BR aligned_alloc (3),
except for the CAVEATS documented below.
.\" The behavior of memalign() for size==0 is as for posix_memalign()
.\" but no standards govern this.
.SH ATTRIBUTES
For an explanation of the terms used in this section, see
.BR attributes (7).
.TS
allbox;
lbx lb lb
l l l.
Interface	Attribute	Value
T{
.na
.nh
.BR memalign ()
T}	Thread safety	MT-Safe
.TE
.SH VERSIONS
On some systems
.BR memalign ()
is declared in
.I <stdlib.h>
instead of
.IR <malloc.h> .
.SH STANDARDS
None.
.SH HISTORY
glibc 2.0.
SunOS 4.1.3.
.SH CAVEATS
.BR memalign ()
may not check that the
.I alignment
argument is correct.
.P
Some systems provide no way to reclaim memory allocated with
.BR memalign ()
(because one can pass to
.BR free (3)
only a pointer obtained from
.BR malloc (3),
while, for example,
.BR memalign ()
would call
.BR malloc (3)
and then align the obtained value).
The glibc implementation
allows memory obtained from
.BR memalign ()
to be reclaimed with
.BR free (3).
.SH SEE ALSO
.BR aligned_alloc (3)