Why does the following c code work in turbo c and not in devc++?

Question

I have the following piece of code:

char *str;
gets(str);

Now it works in turbo c but fails to in devc.

I have to add the following in order to make it work in devC++.

char *str = malloc(5);

Can anyone explain, why is it so?

Also, which one is authentic and a more correct form of coding.

Answer 1

that

char *str;
gets(str);

just cannot be right. str is not initialized, and gets recieves the pointer by value so it cannot allocate it internally. You're just lucky/unlucky with undefined behaviour.

which one is authentic and a more correct form of coding ?

None of the above. don't use gets. It's unsafe because you cannot limit the input size. Use fgets with specified size (and an allocated buffer of course!)

#include <stdio.h>
char buffer[20];
fgets(buffer, sizeof(buffer), stdin); // reads at most 19 chars + null-termination

or scanf with size limit (note the -1): scanf("%19s",buffer);

Answer 2

gets(str);

It shouldnt work even in turbo c++ because you have not allocated the space to str. correct way

 str = (char *)malloc(sizeof(char) * (length+1));