Member array and pointer in banyan loan C language structure

Banyan loan implementation of the following Test function , The analysis will output the above results and what problems exist in the code .

1、 Pen test 1
void GetMemory(char* p)
{
    p = (char*)malloc(100);
}

void Test(void)
{
    char* str = NULL;
    GetMemory(str);  
    strcpy(str, "hello world");
    printf(str);  // take str Send the first address of to printf function , feasible
Banyan loan analysis ：

There are three problems in the above program ：

First of all ： Banyan loan in Test Call in function GetMemory Function time , The relay will be str Value , therefore GetMemory The parameters of the function p It's just str A temporary copy of , And str It doesn't matter , Will be developed dynamically 100 Bytes are passed to the pointer p Management is not right str Any impact ; And banyan loan even if the transmission is str The address of ,malloc Function application space may also fail ;

second ： Banyan loan due to GetMemory Function does not make str Get space , therefore str Still NULL, Call at this time strcpy Function will cause program error ;

Third ： Banyan loan code is not for dynamic development 100 Byte space free, Memory leaks can result ;