Question

I have problem allocating memory for array of structure containing char*.

I have one stracture “Person”

typedef struct
{
    char *name;
    char *surname;
    char *phonenumber;
} Person;

What I want to do is to read some data from file and fill the array (Person *array) of people where I have to dynamically allocate memory.

---

At the moment, I have something like that:

array = malloc(sizeof(Person) * arraysize);
Person *buff;
char   text[100];
char   *result;

for(i=0; i<arraysize; i++)
{
    buff = &array[i];
    fgets(text, 100, f );

    //Read first name
    result = strtok(text,":");
    buff->name= malloc(strlen(result));
    buff->name= result;

    //Read surname
    result  = strtok(0,":");
    buff->surname = malloc(strlen(result));
    buff->surname = result;

    //Read phone number
    result = strtok(0, ":");
    buff->phonenumber = malloc(strlen(result));
    buff->phonenumber = result;
}

When I print out the whole array I don’t get any valid data. I’m wondering what am I doing wrong. I appreicate for your answers in advance!

Answer 1

The problem is:

result = strtok(text,":");
buff->name= malloc(strlen(result));
buff->name= result;

You need to use strcpy for copying and also the length of the malloced string should be one more than the string length to accommodate the NUL char.

buff->name= malloc(strlen(result) + 1);