链表只维护指针域时，按位置删除时程序报错：

#include "linklist.h"

//typedef struct Linknode {
//	
//	struct Linknode* next;
//}Linklist;
//typedef struct LLlist {
//Linklist linknodehead;
//	int size;
//}Lllist;
linklist  initlinklist() {
	
	Lllist* addrlist = malloc(sizeof(Lllist));
	if (addrlist==NULL)
	{
		return  NULL;
	}
	addrlist->phead.next = NULL;
	addrlist->size = 0;
	return addrlist;
}
void insertlinklist(linklist addr, int pos, void* data) {
	if (data == NULL | addr == NULL)
		return NULL;
	Lllist* addrlist = addr;
	if (pos>addrlist->size|pos<0)
	{
		pos = addrlist->size;
	}
	Linklist* pcurr = &addrlist->phead;
	for (int  i = 0; i < pos; i++)
	{
		pcurr = pcurr->next;
	}
	Linklist* newnode = data;
	newnode->next = pcurr->next;
	pcurr->next = newnode;
	addrlist->size++;
	return;
}
void foreachlinklist(linklist addr,void myprint(void *addr)) {
	if (addr==NULL)
	{
		return NULL;
	}
	Lllist* addrlist = addr;
	Linklist* pcurr = addrlist->phead.next;
	for (int  i = 0; i < addrlist->size; i++)
	{
		myprint(pcurr);
		pcurr = pcurr->next;
	}
	return;
}
void delebyposlist(linklist addr, int pos) {
	Lllist* addrlist = addr;
	if (addr==NULL||pos<0||pos>addrlist->size)
	{
		return;
	}
	Linklist* pcurr = &addrlist->phead;
	for (int i = 0; i < pos; i++)
	{
		pcurr = pcurr->next;
	}
	Linklist* temp = pcurr->next;
	pcurr->next = pcurr->next->next;
	addrlist->size--;
	temp = NULL;
	return;
}

temp指向的数据为用户数据，数据是用户管理开辟的，由用户决定数据去留，只需将其指向NULL，避免出现野指针即可