changing value from function

I want to change a 2dim char array in a function.

I allocate the space like

char **u;
u = new char * [ MAX_DEPTH ];
for (i=0; i<MAX_DEPTH; i++)
    u[ i ] = new char [ BUFFER_SIZE ];

the function looks like

rem(char ***arr, int max_length, char *url)
{
    int idx=0;
    char * p;
    int i;

    p = strtok (url,"/"); 

    while (p != NULL && idx < max_length)
    {

        for (  i=0; i<maxUrlSize-1 && p[i] != '\0'; i++)
            (*arr)[idx][i] = p[i];
        for (     ; i< maxUrlSize-1; i++)
            (*arr)[idx][开发者_如何学Ci] = '\0';
    }
}

the function will be used in my main program.

rem( &u, MAX_LEN, url);

but after leaving the function there is nothing in. Could someone explain me how to use pointers in this way?

---

You need to change the reference to tmp in your function, to arr. You aren't accessing the parameter arr at all. Also, you do not need char *** here, since you aren't changing the space allocated to u. Instead, you should have parameter char **arr, which you access as arr[i][j]. And you should then pass u to rem, rather than &u.