4 * This file contains general linked list routines.
6 * Copyright 1990,1991 by the Massachusetts Institute of Technology
7 * For distribution and copying rights, see the file "mit-copyright.h"
10 #include <afsconfig.h>
11 #include <afs/param.h>
15 #include "linked_list.h"
25 void ll_init(linked_list *list)
28 * List must point to a linked list structure. It is not acceptable
29 * to pass a null pointer to this routine.
33 * Initializes the list to be one with no elements. If list is
34 * NULL, prints an error message and causes the program to crash.
38 fprintf(stderr, "Error: calling ll_init with null pointer.\n");
42 /* This sets everything to zero, which is what we want. */
43 bzero((char *)list, sizeof(linked_list));
46 ll_node *ll_add_node(linked_list *list, ll_end which_end)
51 * Adds a node to one end of the list (as specified by which_end)
52 * and returns a pointer to the node added. which_end is of type
53 * ll_end and should be either ll_head or ll_tail as specified in
54 * list.h. If there is not enough memory to allocate a node,
55 * the program returns NULL.
60 if ((node = calloc(1, sizeof(ll_node))) != NULL) {
61 if (list->nelements == 0) {
69 list->first->prev = node;
70 node->next = list->first;
74 list->last->next = node;
75 node->prev = list->last;
79 fprintf(stderr, "%s%s",
80 "ll_add_node got a which_end parameter that ",
81 "it can't handle.\n");
92 int ll_delete_node(linked_list *list, ll_node *node)
97 * If node is in list, deletes node and returns LL_SUCCESS.
98 * Otherwise, returns LL_FAILURE. If node contains other data,
99 * it is the responsibility of the caller to free it. Also, since
100 * this routine frees node, after the routine is called, "node"
101 * won't point to valid data.
104 int status = LL_SUCCESS;
105 ll_node *cur_node = NULL;
108 if (list->nelements == 0)
111 for (cur_node = list->first; (cur_node != NULL) && !found;
112 cur_node = cur_node->next) {
113 if (cur_node == node) {
116 cur_node->prev->next = cur_node->next;
118 list->first = cur_node->next;
121 cur_node->next->prev = cur_node->prev;
123 list->last = cur_node->prev;
139 /* ll_add_data is a macro defined in linked_list.h */
141 /* This routine maintains a list of strings preventing duplication. */
142 int ll_string(linked_list *list, ll_s_action action, char *string)
144 int status = LL_SUCCESS;
149 /* Scan the list until we find the string in question */
150 for (cur_node = list->first; cur_node && (status == FALSE);
151 cur_node = cur_node->next)
152 status = (strcmp(string, cur_node->data) == 0);
155 /* Add a string to the list. */
156 if (!ll_string(list, ll_s_check, string)) {
157 if ((cur_node = ll_add_node(list, ll_tail))) {
159 if ((new_string = calloc(strlen(string) + 1, sizeof(char)))) {
160 strcpy(new_string, string);
161 ll_add_data(cur_node, new_string);
171 /* This should never happen */