MALLOC(3)						     Library Functions Manual							 MALLOC(3)

NAME

       malloc, free, realloc, calloc - main memory allocator

SYNOPSIS

       char *malloc(size)
       unsigned size;

       free(ptr)
       char *ptr;

       char *realloc(ptr, size)
       char *ptr;
       unsigned size;

       char *calloc(nelem, elsize)
       unsigned nelem, elsize;

DESCRIPTION

       Malloc  and  free  provide  a simple general-purpose memory allocation package.	Malloc returns a pointer to a block of at least size bytes
       beginning on a word boundary.

       The argument to free is a pointer to a block previously allocated by malloc; this space is made available for further allocation,  but  its
       contents are left undisturbed.

       Needless to say, grave disorder will result if the space assigned by malloc is overrun or if some random number is handed to free.

       Malloc  allocates  the  first  big enough contiguous reach of free space found in a circular search from the last block allocated or freed,
       coalescing adjacent free blocks as it searches.	It calls sbrk (see break(2)) to get more memory from the system when there is no  suitable
       space already free.

       Realloc	changes  the  size of the block pointed to 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.

       Realloc also works if ptr points to a block freed since the last call of malloc, realloc or calloc; thus  sequences  of	free,  malloc  and
       realloc can exploit the search strategy of malloc to do storage compaction.

       Calloc allocates space for an array of nelem elements of size elsize.  The space is initialized to zeros.

       Each  of  the  allocation routines returns a pointer to space suitably aligned (after possible pointer coercion) for storage of any type of
       object.

DIAGNOSTICS

       Malloc, realloc and calloc return a null pointer (0) if there is no available memory or if the arena has been detectably corrupted by stor-
       ing outside the bounds of a block.  Malloc may be recompiled to check the arena very stringently on every transaction; see the source code.

BUGS

       When realloc returns 0, the block pointed to by ptr may be destroyed.

																	 MALLOC(3)