怎么查看动态分配内存空间的大小(GNU Linux下C语言版) ，经过几番纠结，终于找到了GNU like UNIX平台下得到malloc后的大小的方法，
microsoft有_msize可完成类似功能，现将测试代码甩上来，以咨参考
/********************************************************************
* Function: Test malloc and realloc,get malloc size
* Author : Samson
* Date : 11/23/2011
* Test platform:
* GNU Linux version 2.6.29.4
* gcc version 4.4.0 20090506 (Red Hat 4.4.0-4) (GCC)
* Online citations: ?malloc+3
* *****************************************************************/
#include <stdio.h>
#include <stdlib.h>
#include <malloc.h>
int
main()
{
char *strP, *tem2P;
int ntem;
strP = malloc(20);
ntem = malloc_usable_size(strP);
printf("first malloc_usable_size is %d\n", ntem);
tem2P = strP;
if(NULL != realloc(strP, 100))
{
ntem = malloc_usable_size(strP);
printf("realloc malloc_usable_size is %d\n", ntem);
}
free(tem2P);
exit(0);
}
run result:
[root@UFO]# ./a.out
first malloc_usable_size is 20
realloc malloc_usable_size is 100