Simple lists in C

list.c

#include <stdio.h>
#include <stdlib.h>


typedef struct elem {
    void *data;
    struct elem *next;
} elem_t;


int main(int argc, char **argv) {

    char *line;
    size_t n;

    elem_t *e, *l;

// allocate list l
    l = (elem_t*) malloc(sizeof(elem_t));
// and its metadata
    l->data = malloc(sizeof(int));

// read all lines from STDIN
    for (e=l; getline(&line, &n, stdin) != -1; e = e->next) {

        // append line to l
	e->next = (elem_t*) malloc(sizeof(elem_t)); 
        e->next->data = line;

        // make getline allocate resources for another round
        line=NULL;
        n=0;
    }


// this is how you traverse l
    for (e=l; e=e->next; ) printf("%s", (char*) e->data);

// e.g.
    for (e=l, n=0; e=e->next; n++);
    printf("No. of lines read: %ld\n", n);


// free l and its elements
    while (l) {
        e = l->next;
        free(l->data);
        free(l);
        l = e;
    }

    return 0;
}