Originální popis anglicky: 
cfree - free allocated memory
Návod, kniha: Linux Programmer's Manual
 
#include <stdlib.h>
 
/* In SunOS 4 */
int cfree(void *ptr);
 
/* In glibc or FreeBSD libcompat */
void cfree(void *ptr);
 
/* In SCO OpenServer */
void cfree(char *ptr, unsigned num, unsigned size);
 
/* In Solaris watchmalloc.so.1 */
void cfree(void *ptr, size_t nelem, size_t elsize);
This function should never be used. Use 
free(3) instead.
In glibc, the function 
cfree() is a synonym for 
free(3),
  "added for compatibility with SunOS".
Other systems have other functions with this name. The declaration is sometimes
  in 
<stdlib.h> and sometimes in 
<malloc.h>.
Some SCO and Solaris versions have malloc libraries with a 3-argument
  
cfree(), apparently as an analog to 
calloc(3).
If you need it while porting something, add
 
#define cfree(p, n, s) free((p))
 
to your file.
A frequently asked question is "Can I use 
free() to free memory
  allocated with 
calloc(), or do I need 
cfree()?" Answer: use
  
free().
An SCO manual writes: "The cfree routine is provided for compliance to the
  iBCSe2 standard and simply calls free. The num and size arguments to cfree are
  not used."
The SunOS version of 
cfree() (which is a synonym for 
free())
  returns 1 on success and 0 on failure. In case of error, 
errno is set
  to EINVAL: the value of 
ptr was not a pointer to a block previously
  allocated by one of the routines in the malloc() family.
The 3-argument version of 
cfree() as used by SCO conforms to the iBCSe2
  standard: Intel386 Binary Compatibility Specification, Edition 2.