scanf a string in a char pointer

Question

I want to scan a string and point a char pointer to this scanned string.

int main(int argc, char *argv[]) {

    char *string;
    scanf("%s",&string);
    printf("%s\n",string);

}

But gives a warning saying

warning: format '%s' expects argument of type 'char *', but argument 2 has type 'char **'

How do I scan a string in a char * without warnings.

Edit : It worked for the below code with warnings and I drilled down it to the above one so to be very specific.

int main(int argc, char *argv[]) {

    int n = 2;

    char *strings[2];
    for(int i = 0; i < n; i++){
        scanf("%s",&strings[i]);
        printf("%s\n",&strings[i]);
    }

}

Allocate memory for string variable first then pass only `string` instead `&string`. — Jeyaram, Jun 20 '16 at 11:14
In other words, you're asking how to make the compiler error go away when you haven't figured out how to allocate a memory buffer yet. — Warren P, Jun 20 '16 at 11:15
... or use a fixed-length string. It depends on what you're planning on reading. — Kusalananda, Jun 20 '16 at 11:16
When you say "this works", does that mean you actually tested it? Because I don't see how it does anything but crash. — interjay, Jun 20 '16 at 11:18
@interjay You're most likely correct, but then, It's UB..... — Sourav Ghosh, Jun 20 '16 at 11:19

Sourav Ghosh · Accepted Answer · 2016-06-20T11:20:53.323

First of all, %s in scanf() expects a pointer to char, not a pointer to pointer to char.

Quoting C11, chapter §7.21.6.2 / p12, fscanf() (emphasis mine)

s
Matches a sequence of non-white-space characters.²⁸⁶⁾

If no l length modifier is present, the corresponding argument shall be a pointer to the initial element of a character array large enough to accept the sequence and a terminating null character, which will be added automatically. [...]

Change

scanf("%s",&string);

to

scanf("%s",string);

That said, you need to allocate memory to string before you actually try to scan into it. Otherwise, you'll end up using uninitialized pointer which invokes undefined behavior.

how to allocate memory beforehand? – shashank shekhar singh Jan 24 '22 at 18:10 — shashank shekhar singh, Jan 24 '22 at 18:10

scanf a string in a char pointer

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