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.TH MALLOC "3P" 2013 "IEEE/The Open Group" "POSIX Programmer's Manual"

.SH PROLOG

This manual page is part of the POSIX Programmer's Manual.

The Linux implementation of this interface may differ (consult

the corresponding Linux manual page for details of Linux behavior),

or the interface may not be implemented on Linux.

.SH NAME

malloc

\(em a memory allocator

.SH SYNOPSIS

.LP

.nf

#include <stdlib.h>

.P

void *malloc(size_t \fIsize\fP);

.fi

.SH DESCRIPTION

The functionality described on this reference page is aligned with the

ISO\ C standard. Any conflict between the requirements described here and the

ISO\ C standard is unintentional. This volume of POSIX.1\(hy2008 defers to the ISO\ C standard.

.P

The

\fImalloc\fR()

function shall allocate unused space for an object whose size in

bytes is specified by

.IR size

and whose value is unspecified.

.P

The order and contiguity of storage allocated by successive calls to

\fImalloc\fR()

is unspecified. The pointer returned if the allocation succeeds shall

be suitably aligned so that it may be assigned to a pointer to any type

of object and then used to access such an object in the space allocated

(until the space is explicitly freed or reallocated). Each such

allocation shall yield a pointer to an object disjoint from any other

object. The pointer returned points to the start (lowest byte address)

of the allocated space. If the space cannot be allocated, a null

pointer shall be returned. If the size of the space requested is 0, the

behavior is implementation-defined: the value returned shall be either

a null pointer or a unique pointer.

.SH "RETURN VALUE"

Upon successful completion with

.IR size

not equal to 0,

\fImalloc\fR()

shall return a pointer to the allocated space. If

.IR size

is 0, either a null pointer or a unique pointer that can be

successfully passed to

\fIfree\fR()

shall be returned. Otherwise, it shall return a null pointer

and set

.IR errno

to indicate the error.

.SH ERRORS

The

\fImalloc\fR()

function shall fail if:

.TP

.BR ENOMEM

Insufficient storage space is available.

.LP

.IR "The following sections are informative."

.SH EXAMPLES

None.

.SH "APPLICATION USAGE"

None.

.SH RATIONALE

None.

.SH "FUTURE DIRECTIONS"

None.

.SH "SEE ALSO"

.IR "\fIcalloc\fR\^(\|)",

.IR "\fIfree\fR\^(\|)",

.IR "\fIgetrlimit\fR\^(\|)",

.IR "\fIposix_memalign\fR\^(\|)",

.IR "\fIrealloc\fR\^(\|)"

.P

The Base Definitions volume of POSIX.1\(hy2008,

.IR "\fB<stdlib.h>\fP"

.SH COPYRIGHT

Portions of this text are reprinted and reproduced in electronic form

from IEEE Std 1003.1, 2013 Edition, Standard for Information Technology

-- Portable Operating System Interface (POSIX), The Open Group Base

Specifications Issue 7, Copyright (C) 2013 by the Institute of

Electrical and Electronics Engineers, Inc and The Open Group.

(This is POSIX.1-2008 with the 2013 Technical Corrigendum 1 applied.) In the

event of any discrepancy between this version and the original IEEE and

The Open Group Standard, the original IEEE and The Open Group Standard

is the referee document. The original Standard can be obtained online at

http://www.unix.org/online.html .

Any typographical or formatting errors that appear

in this page are most likely

to have been introduced during the conversion of the source files to

man page format. To report such errors, see

https://www.kernel.org/doc/man-pages/reporting_bugs.html .