Easy-to-use linked list operation library.

1. linklist. c

#include "linklist.h"/* Allocate new list. */struct list *list_new (void){

  return (struct list *)calloc(1, sizeof(struct list));

}/* Free list. */voidlist_free (struct list *l){  free(l);

}/* Allocate new listnode.  Internal use only. */static struct listnode *listnode_new (void){  return (struct listnode *)calloc(1,sizeof (struct listnode));}/* Free listnode. */static voidlistnode_free (struct listnode *node){  free(node);}/* Add new data to the list. */voidlistnode_add (struct list *list, void *val){  struct listnode *node;    assert (val != NULL);    node = listnode_new ();  node->prev = list->tail;  node->data = val;  if (list->head == NULL)    list->head = node;  else    list->tail->next = node;  list->tail = node;  list->count++;}/* * Add a node to the list.  If the list was sorted according to the * cmp function, insert a new node with the given val such that the * list remains sorted.  The new node is always inserted; there is no * notion of omitting duplicates. */voidlistnode_add_sort (struct list *list, void *val){  struct listnode *n;  struct listnode *new;    assert (val != NULL);    new = listnode_new ();  new->data = val;  if (list->cmp)    {      for (n = list->head; n; n = n->next){  if ((*list->cmp) (val, n->data) < 0)    {          new->next = n;      new->prev = n->prev;      if (n->prev)n->prev->next = new;      elselist->head = new;      n->prev = new;      list->count++;      return;    }}    }  new->prev = list->tail;  if (list->tail)    list->tail->next = new;  else    list->head = new;  list->tail = new;  list->count++;}voidlistnode_add_after (struct list *list, struct listnode *pp, void *val){  struct listnode *nn;    assert (val != NULL);    nn = listnode_new ();  nn->data = val;  if (pp == NULL)    {      if (list->head)list->head->prev = nn;      elselist->tail = nn;      nn->next = list->head;      nn->prev = pp;      list->head = nn;    }  else    {      if (pp->next)pp->next->prev = nn;      elselist->tail = nn;      nn->next = pp->next;      nn->prev = pp;      pp->next = nn;    }  list->count++;}/* Delete specific date pointer from the list. */voidlistnode_delete (struct list *list, void *val){  struct listnode *node;  assert(list);  for (node = list->head; node; node = node->next)    {      if (node->data == val){  if (node->prev)    node->prev->next = node->next;  else    list->head = node->next;  if (node->next)    node->next->prev = node->prev;  else    list->tail = node->prev;  list->count--;  listnode_free (node);  return;}    }}/* Return first node's data if it is there.  */void *listnode_head (struct list *list){  struct listnode *node;  assert(list);  node = list->head;  if (node)    return node->data;  return NULL;}/* Delete all listnode from the list. */voidlist_delete_all_node (struct list *list){  struct listnode *node;  struct listnode *next;  assert(list);  for (node = list->head; node; node = next)    {      next = node->next;      if (list->del)(*list->del) (node->data);      listnode_free (node);    }  list->head = list->tail = NULL;  list->count = 0;}/* Delete all listnode then free list itself. */voidlist_delete (struct list *list){  assert(list);  list_delete_all_node (list);  list_free (list);}/* Lookup the node which has given data. */struct listnode *listnode_lookup (struct list *list, void *data){  struct listnode *node;  assert(list);  for (node = listhead(list); node; node = listnextnode (node))    if (data == listgetdata (node))      return node;  return NULL;}/* Delete the node from list.. */voidlist_delete_node (struct list *list, struct listnode *node){  if (node->prev)    node->prev->next = node->next;  else    list->head = node->next;  if (node->next)    node->next->prev = node->prev;  else    list->tail = node->prev;  list->count--;  listnode_free (node);}voidlist_add_node_prev (struct list *list, struct listnode *current, void *val){  struct listnode *node;    assert (val != NULL);    node = listnode_new ();  node->next = current;  node->data = val;  if (current->prev == NULL)    list->head = node;  else    current->prev->next = node;  node->prev = current->prev;  current->prev = node;  list->count++;}voidlist_add_node_next (struct list *list, struct listnode *current, void *val){  struct listnode *node;    assert (val != NULL);    node = listnode_new ();  node->prev = current;  node->data = val;  if (current->next == NULL)    list->tail = node;  else    current->next->prev = node;  node->next = current->next;  current->next = node;  list->count++;}voidlist_add_list (struct list *l, struct list *m){  struct listnode *n;  for (n = listhead (m); n; n = listnextnode (n))    listnode_add (l, n->data);}

2. linklist. h

#ifndef __LINKLIST_H#define __LINKLIST_H/* listnodes must always contain data to be valid. Adding an empty node * to a list is invalid */struct listnode {  struct listnode *next;  struct listnode *prev;    /* private member, use getdata() to retrieve, do not access directly */  void *data;};struct list {  struct listnode *head;  struct listnode *tail;  /* invariant: count is the number of listnodes in the list */  unsigned int count;  /*   * Returns -1 if val1 < val2, 0 if equal?, 1 if val1 > val2.   * Used as definition of sorted for listnode_add_sort   */  int (*cmp) (void *val1, void *val2);  /* callback to free user-owned data when listnode is deleted. supplying   * this callback is very much encouraged!   */  void (*del) (void *val);};#define listnextnode(X) ((X) ? ((X)->next) : NULL)#define listhead(X) ((X) ? ((X)->head) : NULL)#define listtail(X) ((X) ? ((X)->tail) : NULL)#define listcount(X) ((X)->count)#define list_isempty(X) ((X)->head == NULL && (X)->tail == NULL)#define listgetdata(X) (assert((X)->data != NULL), (X)->data)/* Prototypes. */extern struct list *list_new(void); /* encouraged: set list.del callback on new lists */extern void list_free (struct list *);extern void listnode_add (struct list *, void *);extern void listnode_add_sort (struct list *, void *);extern void listnode_add_after (struct list *, struct listnode *, void *);extern void listnode_delete (struct list *, void *);extern struct listnode *listnode_lookup (struct list *, void *);extern void *listnode_head (struct list *);extern void list_delete (struct list *);extern void list_delete_all_node (struct list *);extern void list_delete_node (struct list *, struct listnode *);extern void list_add_node_prev (struct list *, struct listnode *, void *);extern void list_add_node_next (struct list *, struct listnode *, void *);extern void list_add_list (struct list *, struct list *);/* List iteration macro.  * Usage: for (ALL_LIST_ELEMENTS (...) { ... } * It is safe to delete the listnode using this macro. */#define ALL_LIST_ELEMENTS(list,node,nextnode,data)   (node) = listhead(list), ((data) = NULL);   (node) != NULL &&     ((data) = listgetdata(node),(nextnode) = node->next, 1);   (node) = (nextnode), ((data) = NULL)/* read-only list iteration macro. * Usage: as per ALL_LIST_ELEMENTS, but not safe to delete the listnode Only * use this macro when it is *immediately obvious* the listnode is not * deleted in the body of the loop. Does not have forward-reference overhead * of previous macro. */#define ALL_LIST_ELEMENTS_RO(list,node,data)   (node) = listhead(list), ((data) = NULL);  (node) != NULL && ((data) = listgetdata(node), 1);   (node) = listnextnode(node), ((data) = NULL)/* these *do not* cleanup list nodes and referenced data, as the functions * do - these macros simply {de,at}tach a listnode from/to a list. */ /* List node attach macro.  */#define LISTNODE_ATTACH(L,N)   do {     (N)->prev = (L)->tail;     if ((L)->head == NULL)       (L)->head = (N);     else       (L)->tail->next = (N);     (L)->tail = (N);     (L)->count++;   } while (0)/* List node detach macro.  */#define LISTNODE_DETACH(L,N)   do {     if ((N)->prev)       (N)->prev->next = (N)->next;     else       (L)->head = (N)->next;     if ((N)->next)       (N)->next->prev = (N)->prev;     else       (L)->tail = (N)->prev;     (L)->count--;   } while (0)#endif /* __LINKLIST_H */

Easy-to-use linked list operation library.