我試圖使用memcpy函數連接一個字符,但是,在memcpy之後,我得到了一個奇怪的緩衝區長度。請參閱下面在C++ memcpy後得到strlen
int main()
{
uint8 txbuffer[13]={0};
uint8 uibuffer[4] = "abc";
uint8 rxbuffer[4] = "def";
uint8 l[2]="g";
int index = 1;
cout << strlen((char*)txbuffer) <<endl;
memcpy(&txbuffer[1],&uibuffer, strlen((char*)uibuffer));
index+=strlen((char*)uibuffer);
cout <<"after first memcpy: "<< strlen((char*)txbuffer) <<endl;
memcpy(&txbuffer[index],&rxbuffer, strlen((char*)uibuffer));
cout <<"after second memcpy: "<< strlen((char*)txbuffer) <<endl;
memcpy(&txbuffer[0],&l, strlen((char*)l));
cout <<"after third memcpy: "<< strlen((char*)txbuffer) <<endl;
for (int i = 0; i < sizeof(txbuffer); i += 1)
{
cout << (int(txbuffer[i]))<<" : "<< char(int(txbuffer[i]))<<endl;
}
return 0;
}
輸出代碼是:
after first memcpy: 0
after second memcpy: 0
after third memcpy: 7
103 : g
97 : a
98 : b
99 : c
100 : d
101 : e
102 : f
0 :
0 :
0 :
0 :
0 :
0 :
我的問題是,爲什麼第一的memcpy後,緩衝區的strlen的仍然是零?