HP-UX Reference (11i v3 07/02) - 3 Library Functions A-M (vol 6)

m
malloc(3C) malloc(3C)
NAME
malloc(), alloca(), calloc(), free(), mallinfo(), mallopt(), memorymap(), realloc(), valloc() - main memory allo-
cator
SYNOPSIS
#include <stdlib.h>
void *malloc(size_t size);
void *calloc(size_t nelem, size_t elsize);
void free(void *ptr);
void *realloc(void *ptr, size_t size);
void *valloc(size_t size);
void memorymap(int show_stats);
(Obsoleted)
alloca()
#include <alloca.h>
void *alloca(size_t size);
System V Synopsis
#include <malloc.h>
char *malloc(unsigned size);
char *calloc(unsigned nelem, unsigned elsize);
void free(char *ptr);
int mallopt(int cmd, int value);
char *realloc(char *ptr, unsigned size);
struct mallinfo mallinfo(void);
Remarks
The functionality in the old
malloc() package has been incorporated into malloc(). The library
(
/usr/lib/libmalloc.a
) corresponding to the -lmalloc linker option is now an empty library on
PA-RISC based systems only; it does not exist on Itanium-based systems. Makefiles that reference this
library on PA-RISC based systems will continue to work, but they will not work on Itanium-based sys-
tems.
Obsolescent Interfaces
memorymap() has been deprecated at HP-UX 11i Version 1 and is now obsolete. The
mal-
linfo()
function is more useful for malloc statistics.
DESCRIPTION
The functions described here provide a simple, general purpose memory allocation package:
malloc() Allocates space for a block of at least size bytes, but does not initialize the space.
calloc() Allocates space for an array of nelem elements, each of size elsize bytes, and initializes
the space to zeros. Actual amount of space allocated will be at least nelem * elsize
bytes.
realloc() Changes the size of the block pointed to by ptr to size bytes and returns a pointer to
the (possibly moved) block. Existing contents are unchanged up to the lesser of the
new and old sizes. If ptr is a NULL pointer, realloc() behaves like malloc()
for the specified size. If size is zero and ptr is not a NULL pointer, the object it points
to is freed and NULL is returned. realloc() of blocks with special alignments,
such as those created by valloc(), is not supported.
valloc() Allocates space for a block of at least size bytes starting on a boundary aligned to a
multiple of the value returned by sysconf(__SC_PAGESIZE). This space is unini-
tialized.
HP-UX 11i Version 3: February 2007 − 1 − Hewlett-Packard Company 775