Programming

#include <stdio.h>
#include <stdlib.h>
#include <assert.h>

int f1(char **str_);

int main(int argc, char **argv)
{
    char *str = NULL;

    f1(&str);     
    printf("str : %s\n", *str);

    str = realloc(str, (size_t) 0);   
    assert(str == NULL);

    return 0;
}

int f1(char **str_)
{
    if ((*str_ = realloc(*str_, sizeof(char) * 12)) == NULL)
    {
        fprintf(stderr,"realloc() failed\n");
        exit(3);
    }

    (*str_) = "hello there";

    return 0;
}

 strcpy( *str_, "hello there" );