linux c 分配释放内存 sbrk分配,brk释放

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include <sys/types.h>

#include <unistd.h>

int main(int argc,char* argv[])

{

 void* pfirst = sbrk(sizeof(int));

 *(int*)pfirst = 4;

 void* ptwo = sbrk(sizeof(double));

 *(double*)ptwo = 4.68;

 

 printf("%d -- %g\n",*(int*)pfirst,*(double*)ptwo);

 

 int ret = brk(pfirst);

 if(ret == -1) perror("brk"),exit(-1);

 

 

 return 0;

}