Treesort - string array

#include "stdio.h"
#include "string.h"
#include "stdlib.h"

struct tnode
{
char *str;
struct tnode *left;
struct tnode *right;
};

void insert(struct tnode **p, char *value);
void print(struct tnode *root);

int main(void)
{
char line[1024];
struct tnode *root;

root = NULL;
while((fgets(line, 1024, stdin)) != NULL)
insert(&root, line);

print(root);
return 0;
}

/* call by reference .. ! */
void insert(struct tnode **p, char *value)
{
if(!*p) {
*p = (struct tnode *)malloc(sizeof(struct tnode));
(*p)->left = (*p)->right = NULL;
(*p)->str = strdup(value);
return;
}

if(strcmp(value, (*p)->str) < 0)
insert(&(*p)->left, value);
else
insert(&(*p)->right, value);
}

/* inorder binary tree print ... */
void print(struct tnode *root)
{
if(root != NULL)
{
print(root->left);
printf("%s", root->str);
print(root->right);
}
}