Question

I am trying to create a linked list in my program and I am not able to allocate memory to the structure pointer using malloc(). How do I allocate memory to variables in GCC? The sample program is given below. How to make it work in gcc?

#include<stdio.h>
#include <alloc.h>
struct node
{

    int data;
    struct node * link;

};
void insert (struct node *p, int d)
{
    struct node *temp;
    temp = malloc(sizeof(struct node));
        temp->data=d;
    temp->link=NULL;

        if(p==NULL)
        {
            p=temp;
        }
        else{
        while(p->link!=NULL)
            p=p->link;

    p->link=temp;
        }
}
void disp(struct node *p)
{
    while(p!=NULL)
        {
        printf("%d\n",p->data);
        p=p->link;
        }


}

int main()
{

struct node *p;
p=NULL;
insert(p,7);
insert(p,9);
disp(p);

}

The error I’m encountering is:

Line 18: error: alloc.h: No such file or directory
In function 'insert':
Line 13: warning: incompatible implicit declaration of built-in function 'malloc'

Answer 1

malloc is in <stdlib.h>. Include that.

Reading the man page for that function would have given you that information. It’s not compiler-dependent.