[C] Generic Signle-Linked List

[phreak]

#ifndef GSLLIST_H
#define GSLLIST_H

#include <string.h>
#include <stdlib.h>

#define false 0
#define true 1

struct sllist_node_t {
    void * value;
    struct sllist_node_t * next;
};

typedef struct sllist_node_t * pnode;

typedef struct {
    pnode first;
    pnode last;
    int type_size;
} sllist;

void init_sllist(sllist * list, int type_size)
{
    list->first = NULL;
    list->last = NULL;
    list->type_size = type_size;
}

void push_back(sllist * list, void * val)
{
    if(list->first == NULL)
    {
        list->first = malloc(sizeof(struct sllist_node_t));
        list->first->value = malloc(list->type_size);
        memcpy(list->first->value, val, list->type_size);
        list->first->next = NULL;

        list->last = list->first;
    }
    else
    {
        list->last->next = malloc(sizeof(struct sllist_node_t));

        list->last = list->last->next;
        list->last->next = NULL;
        list->last->value = malloc(list->type_size);
        memcpy(list->last->value, val, list->type_size);
    }

}

void free_list(sllist * list)
{
    pnode iter = list->first;
    pnode prev = iter;
    while(iter->next != NULL)
    {
        iter = iter->next;
        free(prev->value);
        free(prev);
        prev = iter;
    }

    free(iter->value);
    free(iter);
}

int iterate(sllist * list, pnode * iter, void * value)
{
    if((*iter) == NULL)
        return false;

    memcpy(value, (*iter)->value, list->type_size);

    (*iter) = (*iter)->next;
    return true;
}

#endif

header : C code - 28 lines - codepad

source : C code - 57 lines - codepad

usage :

#include <stdio.h>
#include "generic_sllist.h"

int main()
{
    sllist list;
    init_sllist(&list, sizeof(int));

    int value = 1;
    push_back(&list, &value);
    value = 2;
    push_back(&list, &value);
    value = 3;
    push_back(&list, &value);

    int vals[] = {4,5,6};

    for(int i = 0; i < 3; i++)
        push_back(&list, &vals[i]);

    pnode iter = list.first;
    while(iterate(&list, &iter, &value))
        printf("%d\n", value);

    free_list(&list);
    return 0;
}

test :

debian-devel ll # gcc -g -std=gnu99 llmain.c generic_sllist.c && ./a.out
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debian-devel ll # valgrind ./a.out
==1916== Memcheck, a memory error detector
==1916== Copyright (C) 2002-2010, and GNU GPL'd, by Julian Seward et al.
==1916== Using Valgrind-3.6.0.SVN-Debian and LibVEX; rerun with -h for copyright info
==1916== Command: ./a.out
==1916==
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==1916==
==1916== HEAP SUMMARY:
==1916==     in use at exit: 0 bytes in 0 blocks
==1916==   total heap usage: 12 allocs, 12 frees, 120 bytes allocated
==1916==
==1916== All heap blocks were freed -- no leaks are possible
==1916==
==1916== For counts of detected and suppressed errors, rerun with: -v
==1916== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 4 from 4)
debian-devel ll #