#include <stdio.h>
#include <stdlib.h>     /*malloc()*/

void int2str(int, char *);

int main()
{
    int i=123;
    char *s = (char *)malloc(sizeof(char));     //remember cast malloc output (char *)
    int2str(i, s);
    printf("%s\n", s);
    return 0;
}

void int2str(int i, char *s){
    sprintf(s, "%d", i);
}

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