/* MALLOC.C: This program allocates memory with
 * malloc, then frees the memory with free.
 */
#include <stdlib.h>         /* Definition of _MAX_PATH */
#include <stdio.h>
#include <malloc.h>
void main( void )
{
   char *string;
   /* Allocate space for a path name */
   string = malloc( _MAX_PATH );
   if( string == NULL )
      printf( "Insufficient memory available\n" );
   else
      printf( "Memory space allocated for path name\n" );
   free( string );
   printf( "Memory freed\n" );
}

/*
#include <stdlib.h> 	For ANSI compatibility (malloc only)
#include <malloc.h> 	Required only for function declarations

Syntax 	void *malloc( size_t size );
	void __based(void) *_bmalloc( __segment seg, size_t size );
	void __far *_fmalloc( size_t size );

void __near *_nmalloc( size_t size );

malloc	
Standards:	ANSI, UNIX
16-Bit:	MS-DOS, QWIN, WIN, WIN DLL
	
_bmalloc, _fmalloc, _nmalloc	
Standards:	None
16-Bit:	MS-DOS, QWIN, WIN, WIN DLL
	

Parameter	Description
size	Bytes to allocate
seg	Based heap segment selector
Functions in the malloc family allocate a memory block of at least size bytes. The block may be larger than size bytes because of space required for alignment and maintenance information. If size is 0, each of these functions allocates a zero-length item in the heap and returns a valid pointer to that item.
The storage space pointed to by the return value is guaranteed to be suitably aligned for storage of any type of object. To get a pointer to a type other than void, use a type cast on the return value.
In large data models (compact-, large-, and huge-model programs), malloc maps to _fmalloc. In small data models (tiny-, small-, and medium-model programs), malloc maps to _nmalloc. The _fmalloc function allocates a memory block of at least size bytes in the far heap, which is outside the default data segment.

The bmalloc function allocates a memory block of at least size bytes in the based heap segment specified by the segment selector seg.

The malloc functions allocate memory in the heap segment specified below:

Function	Heap Segment
malloc	Depends on data model of program
_bmalloc	Based heap segment specified by seg value
_fmalloc	Far heap (outside default data segment)
_nmalloc	Near heap (within default data segment)
The functions listed below call the malloc family of routines. In addition, the startup code uses malloc to allocate storage for the environ/envp and argv strings and arrays.

The following routines call malloc:

_brealloc	fscanf	_putw
calloc	fseek	scanf
_execl	fsetpos	_searchenv
_execle	_fullpath	setvbuf
_execlp	fwrite	_spawnl
_execlpe	getc	_spawnle
_execv	getchar	_spawnlp
_execve	_getcwd	_spawnlpe
_execvp	_getdcwd	_spawnv
_execvpe	gets	_spawnve
fgetc	_getw	_spawnvp
_fgetchar	_nrealloc	_spawnvpe
fgets	_popen	_strdup
fprintf	printf	system
fputc	putc	_tempnam
_fputchar	putchar	ungetc
fputs	_putenv	vfprintf
fread	puts	vprintf
_frealloc		
The following routines call _nmalloc:
_nrealloc 
_ncalloc 
_nstrdup 
realloc (in small data models)
The following routines call _fmalloc:
_frealloc 
_fcalloc 
_fstrdup 
realloc (in large data models)

In Microsoft C version 5.1, the _fmalloc function retried allocating within the default data segment (that is, in the near heap) if sufficient memory was not available outside the default data segment. Since version 6.0, _fmalloc returns NULL under these conditions.

The _freect, _memavl, and _memmax functions called malloc in Microsoft C version 5.1 but do not do so in versions 6.0, 7.0, and this product.

Return Value

The malloc function returns a void pointer to the allocated space. The _nmalloc function returns a ( void __near * ) and _fmalloc returns a ( void __far * ). The _bmalloc function returns a ( void __based( void ) * ).
The _malloc, _fmalloc, and _nmalloc functions return NULL if there is insufficient memory available. The _bmalloc function returns _NULLOFF if there is insufficient memory available.

Always check the return from the malloc function, even if the amount of memory requested is small.


*/