1/***************************************************************************
2 * _ _ ____ _
3 * Project ___| | | | _ \| |
4 * / __| | | | |_) | |
5 * | (__| |_| | _ <| |___
6 * \___|\___/|_| \_\_____|
7 *
8 * Copyright (C) 1998 - 2020, Daniel Stenberg, <daniel@haxx.se>, et al.
9 *
10 * This software is licensed as described in the file COPYING, which
11 * you should have received as part of this distribution. The terms
12 * are also available at https://curl.se/docs/copyright.html.
13 *
14 * You may opt to use, copy, modify, merge, publish, distribute and/or sell
15 * copies of the Software, and permit persons to whom the Software is
16 * furnished to do so, under the terms of the COPYING file.
17 *
18 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
19 * KIND, either express or implied.
20 *
21 ***************************************************************************/
22
23#include "curl_setup.h"
24
25#include <curl/curl.h>
26
27#include "slist.h"
28
29/* The last #include files should be: */
30#include "curl_memory.h"
31#include "memdebug.h"
32
33/* returns last node in linked list */
34static struct curl_slist *slist_get_last(struct curl_slist *list)
35{
36 struct curl_slist *item;
37
38 /* if caller passed us a NULL, return now */
39 if(!list)
40 return NULL;
41
42 /* loop through to find the last item */
43 item = list;
44 while(item->next) {
45 item = item->next;
46 }
47 return item;
48}
49
50/*
51 * Curl_slist_append_nodup() appends a string to the linked list. Rather than
52 * copying the string in dynamic storage, it takes its ownership. The string
53 * should have been malloc()ated. Curl_slist_append_nodup always returns
54 * the address of the first record, so that you can use this function as an
55 * initialization function as well as an append function.
56 * If an error occurs, NULL is returned and the string argument is NOT
57 * released.
58 */
59struct curl_slist *Curl_slist_append_nodup(struct curl_slist *list, char *data)
60{
61 struct curl_slist *last;
62 struct curl_slist *new_item;
63
64 DEBUGASSERT(data);
65
66 new_item = malloc(sizeof(struct curl_slist));
67 if(!new_item)
68 return NULL;
69
70 new_item->next = NULL;
71 new_item->data = data;
72
73 /* if this is the first item, then new_item *is* the list */
74 if(!list)
75 return new_item;
76
77 last = slist_get_last(list);
78 last->next = new_item;
79 return list;
80}
81
82/*
83 * curl_slist_append() appends a string to the linked list. It always returns
84 * the address of the first record, so that you can use this function as an
85 * initialization function as well as an append function. If you find this
86 * bothersome, then simply create a separate _init function and call it
87 * appropriately from within the program.
88 */
89struct curl_slist *curl_slist_append(struct curl_slist *list,
90 const char *data)
91{
92 char *dupdata = strdup(data);
93
94 if(!dupdata)
95 return NULL;
96
97 list = Curl_slist_append_nodup(list, dupdata);
98 if(!list)
99 free(dupdata);
100
101 return list;
102}
103
104/*
105 * Curl_slist_duplicate() duplicates a linked list. It always returns the
106 * address of the first record of the cloned list or NULL in case of an
107 * error (or if the input list was NULL).
108 */
109struct curl_slist *Curl_slist_duplicate(struct curl_slist *inlist)
110{
111 struct curl_slist *outlist = NULL;
112 struct curl_slist *tmp;
113
114 while(inlist) {
115 tmp = curl_slist_append(outlist, inlist->data);
116
117 if(!tmp) {
118 curl_slist_free_all(outlist);
119 return NULL;
120 }
121
122 outlist = tmp;
123 inlist = inlist->next;
124 }
125 return outlist;
126}
127
128/* be nice and clean up resources */
129void curl_slist_free_all(struct curl_slist *list)
130{
131 struct curl_slist *next;
132 struct curl_slist *item;
133
134 if(!list)
135 return;
136
137 item = list;
138 do {
139 next = item->next;
140 Curl_safefree(item->data);
141 free(item);
142 item = next;
143 } while(next);
144}
145