Is scanf() function cause a buffer overflows? please explain this question by comparing the below code?

Question

https://code.sololearn.com/cDN29eVv2K9S/?ref=app
Can this code cause a buffer flow? I raise this question because it access the users input without bothering about the input access limit

Answer 1

For reading string; we can specify buffer size through the format specifier e.g.

scanf("%5s", string_buffer);

There we specify to read max up to 5 characters into <string_buffer>.

The number used in the format specifier must be [buffer size - 1] because the last character must be reserved for string terminator. So allocate 6 characters for reading up to 5 characters, 11 for reading up to of 10 characters, and so on.

http://www.cplusplus.com/reference/cstdio/scanf/

Answer 2

Thanks Ipang
In above code.
I use char array
{
i.e char text[0]
}
To get string input
and
I also use scanf("%5s",text); to set limit for string input.
But it works according to only scanf("%5s",text);
It won't bother about the number(zero) present inside the char array index
{
i.e char text[0];
}
Why, please anybody explain it?

Answer 3

Yogeshwaran
Once I read, that languages such as C or C++ allows you to "shoot yorself" in the foot (or anywhere you want, for that matter). I guess this is one of those cases :D

Answer 4

Ipang thanks for your guidance