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cc [ flag ... ] file ... -lbsdmalloc [ library ... ]

char *malloc( size)
unsigned size;
int free( ptr)
char * ptr;
char *realloc( ptr, size)
char *ptr;
unsigned size;

Description        These routines provide a general-purpose
 memory  allocation package.  They maintain a table of free blocks for efficient
allocation and coalescing of free storage.  When there is no suitable  space
 already  free, the allocation routines call sbrk(2) to get more memory
from the system. Each of the allocation routines returns a pointer  to 
space suitably  aligned  for  storage  of any type of object. Each returns
a null pointer if the request  cannot  be  completed (see DIAGNOSTICS).
malloc()  returns a pointer to  a  block  of  at  least   size bytes, which
is appropriately aligned. 
free() releases a previously allocated block. 
Its  argument is  a  pointer  to a block previously allocated by  malloc()
or  realloc(). 
realloc() changes the size of the block referenced by  ptr
 to size  bytes  and  returns  a pointer to the (possibly moved) block.
 The contents will be unchanged up to the  lesser  of the  new  and  old
sizes.  If unable to honor a reallocation request,  realloc()  leaves its
first argument unaltered.  For backwards  compatibility,   realloc() accepts
a pointer to a block freed since the most recent  call  to   malloc() 
or realloc(). 
Return Valuesmalloc()  and realloc() return a null pointer
if there is not enough available memory.  When realloc() returns NULL, the
block pointed to by ptr is left intact. ErrorsIf malloc() or realloc() returns
 unsuccessfully, errno will be set to indicate the following: ENOMEM  size
bytes of memory exceeds the physical limits of your system, and cannot
be allocated. 
EAGAIN  There is not enough memory available at this point
in time to allocate size bytes of memory; but the application could try
again later. See Alsobrk(2), malloc(3C), malloc(3X), mapmalloc(3X) WarningsUse
of libbsdmalloc renders an application non-SCD compliant. libbsdmalloc routines
are incompatible with the memory allocation routines in the standard C-library
(libc): malloc(3C), alloca(3C), calloc(3C), free(3C), memalign(3C), realloc(3C),
and  valloc(3C). 
NotesUsing  realloc() with a block freed before the most
recent call to   malloc() or realloc() will result in an error.  malloc()
and  realloc()  return a non-NULL pointer if  size is 0. These pointers should
not be dereferenced. 
Always cast the value returned by  malloc()  and  
realloc(). 
Comparative features of bsdmalloc(), malloc(3X), and malloc(3C):


  The  bsdmalloc() routines afford better performance, but are space-inefficient.
  The malloc(3X) routines are space-efficient, but have slower performance.
  The standard, fully SCD-compliant malloc(3C) routines are a trade-off between
 performance and space-efficiency. free()  does not set errno.