calloc
Allocates an array in memory with elements initialized to 0.
void*calloc(size_tnum**,size_tsize);**
| Routine | Required Header | Compatibility |
| calloc | <stdlib.h> and <malloc.h> | ANSI, Win 95, Win NT |
For additional compatibility information, see Compatibility in the Introduction.
Libraries
| LIBC.LIB | Single thread static library, retail version |
| LIBCMT.LIB | Multithread static library, retail version |
| MSVCRT.LIB | Import library for MSVCRT.DLL, retail version |
Return Value
calloc returns a pointer to the allocated space. 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.
Parameters
num
Number of elements
size
Length in bytes of each element
Remarks
The calloc function allocates storage space for an array of num elements, each of length size bytes. Each element is initialized to 0.
calloc calls malloc in order to use the C++ _set_new_mode function to set the new handler mode. The new handler mode indicates whether, on failure, malloc is to call the new handler routine as set by _set_new_handler. By default, malloc does not call the new handler routine on failure to allocate memory. You can override this default behavior so that, when calloc fails to allocate memory, malloc calls the new handler routine in the same way that the new operator does when it fails for the same reason. To override the default, call
_set_new_mode(1)
early in your program, or link with NEWMODE.OBJ.
When the application is linked with a debug version of the C run-time libraries, calloc resolves to _calloc_dbg. For more information about how the heap is managed during the debugging process, see Using C Run-Time Library Debugging Support.
Example
/* CALLOC.C: This program uses calloc to allocate space for
* 40 long integers. It initializes each element to zero.
*/
#include <stdio.h>
#include <malloc.h>
void main( void )
{
long *buffer;
buffer = (long *)calloc( 40, sizeof( long ) );
if( buffer != NULL )
printf( "Allocated 40 long integers\n" );
else
printf( "Can't allocate memory\n" );
free( buffer );
}
Output
Allocated 40 long integers