How to insert string into linked list in c -

i want write function can insert string alphabetically. can declared as;

typedef struct node node; typedef struct node {     char *data;     node *next; };  node *insertion(node *head,char *arr); 

how can define function?

my codes;

#include <stdio.h> #include <stdlib.h> #include <string.h>  typedef struct node node; typedef struct node {     char *data;     node *next; }; node *mylist = 0; void addword(char *word) // add new word list mylist     { node *item,*next;     item = (node *) malloc(sizeof(node));     if ( item==0 ) { printf ("malloc failed \n");  return ; }     strcpy(item->data,word); // copy word new item     item->next = 0; // set next item nothing      if ( mylist == 0 ) // if list empty, make first item         { mylist = item; return ; }      if(strcmp(word,mylist->data) < 0 ) // check if new item comes before first item in old list         { item->next = mylist; mylist = item; return ; }      // check see if item inserted before next item     ( next = mylist ; next ->next != 0 ; next = next ->next )         {         if (strcmp (word, next->next->data) < 0 )             { // insert item before next item.             item ->next = next->next;             next->next = item ; return;             }         }      // there no more items ! add end     next ->next = item;     } 

item = (node *) malloc(sizeof(node)); if ( item==0 ) { printf ("malloc failed \n");  return ; } strcpy(item->data,word); // copy word new item 

item->data non-initialized pointer. should either allocate space copy into, or declare data array in node structure:

char data[somesize];