Question

This was the question asked to me in an interview in c:

#include<stdio.h>
void main(){
  char *ch;
  ch=fun1();
  printf(ch);
}

fun1(){
  char *arr[100];
  strcpy(arr,"name");
  return arr;
}

I was given the above program and was asked to figure out the problems in the above code.
below was my answer

• function declaration is wrong.the
  return type should be char **
• syntax of printf is wrong
• arr scope is limited to the function fun1

then

Interviewer : what would be your solution to the problem?

Me: you need to make the arr variable as global and fix the remaining issues mentioned above.

Interviewer: Dont you think global variables are dangerous?

Me: Yes ofcourse,since we cannot say where it is being accessed in which functions and sometimes it gets almost impossible to find which function has changed the value

Ineterviewer :give me a solution without a global variable

Me:????

what would be your solution for this?
Could anybody pls point out the errors that i have made !!

Answer 1

My solution could be

#include <stdio.h>
#include <string.h>

/* copies "name" to `dst`.
** The caller is responsible for making sure
** `dst` has enough space */
char *fun1(char *dst) {
  strcpy(dst, "name");
  return dst;
}

int main(void) {
  char ch[5];
  printf("%s\n", fun1(ch));
  return 0;
}

---

Here’s just what I found about the snippet …

#include<stdio.h>

I’d add a space before the header: #include <stdio.h>; but that’s just for looks

void main()

WRONG! main returns an int. ALWAYS!
And it should be one of: int main(void) or int main(int argc, char **argv) if you need parameters

{
char *ch;
ch=fun1();

No prototype for fun1 in scope. This makes the compiler assume the function returns a value of type int and the statement tries to assign that value to an object of type char* which is illegal: the compiler must issue a diagnostic here.

printf(ch);
}

fun1()

In C99, it is mandatory to specify a return type; in C89, int is assumed. Also this function definition really should also be a prototype (in both C89 and C99) and specifiy the number and types of parameters (or void if it takes none).

{
char *arr[100];

Why do you need an array of 100 pointers? ???

strcpy(arr,"name");

Oops … no prototype for strcpy() in scope. Also, assuming the strcpy is the one declared in <string.h>, the 1st parameter should be a char* not a char **

return arr;

arr ceases to exist right after the function returns. Its address (the array decays to the address of its first element in this context) is unusable in the calling code.

}