how to use malloc () in Double Pointer in Structure in C -

i have structs:

    typedef struct accont {     char **tel;//list of tel     char **email;//list of emails }acc; 

and

typedef struct _strcol {     int count;      //total of accounts     acc **list; } strcol ; 

i access structure pointer:

strcol index; contato *p; p = (index.list + index.count); 

the question, how use malloc() in function?

i try:

(*p)->tel = (char **) malloc(i * sizeof (char*))  p.tel = (char **) malloc(i * sizeof (char*))  &(*p)->tel = (char **) malloc(i * sizeof (char*)) 

and second malloc save data email or tel

my first post, excuse anything

i'm going assume 'p' acc *p; (i have no idea 'contato' is). anyway ... point show how memory can allocated & tel/email data stored/accessed ... copied tel #/email id demonstrate ... regarding casting void pointer returns malloc, i've seen arguments for/against ... cast (malloc's case cast).

#include <stdio.h> #include <stdlib.h> #include <string.h>  typedef struct accont {         char **tel;    //list of tel         char **email;  //list of emails }acc;  typedef struct _strcol {         int count;      //total of accounts         acc **list; }strcol;  int main() {         int inumaccounts = 5;   // assume there 5 accounts.         int inumtels = 2;       // each account has 2 tel #s.         int inumemails = 3;     // each account has 3 email ids.          strcol index;         acc *p = null;          index.list = (acc **)malloc(5 * sizeof(acc *)); // master list               // of 'acc' pointers i.e. pointer set of pointers.          int i, j;         for(i=0; i<inumaccounts; i++) // go through 5 accounts, 1 @              // time ... , allocate & store tel #s/email ids.         {                 index.list[i] = (acc *)malloc(sizeof(acc));                  p = index.list[i];                  p->tel = (char **)malloc(inumtels * sizeof(char*));                 for(j=0; j<inumtels; j++)                 {                         p->tel[inumtels] = (char *)malloc(11 * sizeof (char)); // 10 digit tel # + 1 byte '\0' ...                         strcpy(p->tel[inumtels], "1234567890");                 }                  p->email = (char **)malloc(inumemails * sizeof(char*));                 for(j=0; j<inumemails; j++)                 {                         p->email[inumemails] = (char *)malloc(51 * sizeof(char)); // 50 char long email id + 1 byte '\0' ...                         strcpy(p->email[inumemails], "kingkong@ihop.yum");                 }         }          for(i=0; i<inumaccounts; i++) // go through 5 accounts, 1 @ time ... , display.         {                 p = index.list[i];                  for(j=0; j<inumtels; j++)                 {                         printf("tel # is: %d\n", p->tel[inumtels]);                 }                  for(j=0; j<inumemails; j++)                 {                         printf("email id is: %s\n", p->email[inumemails]);                 }                  printf("----------\n");         } }