curl/lib/slist.c

145 строки
3.8 KiB
C

/***************************************************************************
* _ _ ____ _
* Project ___| | | | _ \| |
* / __| | | | |_) | |
* | (__| |_| | _ <| |___
* \___|\___/|_| \_\_____|
*
* Copyright (C) 1998 - 2020, Daniel Stenberg, <daniel@haxx.se>, et al.
*
* This software is licensed as described in the file COPYING, which
* you should have received as part of this distribution. The terms
* are also available at https://curl.se/docs/copyright.html.
*
* You may opt to use, copy, modify, merge, publish, distribute and/or sell
* copies of the Software, and permit persons to whom the Software is
* furnished to do so, under the terms of the COPYING file.
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
***************************************************************************/
#include "curl_setup.h"
#include <curl/curl.h>
#include "slist.h"
/* The last #include files should be: */
#include "curl_memory.h"
#include "memdebug.h"
/* returns last node in linked list */
static struct curl_slist *slist_get_last(struct curl_slist *list)
{
struct curl_slist *item;
/* if caller passed us a NULL, return now */
if(!list)
return NULL;
/* loop through to find the last item */
item = list;
while(item->next) {
item = item->next;
}
return item;
}
/*
* Curl_slist_append_nodup() appends a string to the linked list. Rather than
* copying the string in dynamic storage, it takes its ownership. The string
* should have been malloc()ated. Curl_slist_append_nodup always returns
* the address of the first record, so that you can use this function as an
* initialization function as well as an append function.
* If an error occurs, NULL is returned and the string argument is NOT
* released.
*/
struct curl_slist *Curl_slist_append_nodup(struct curl_slist *list, char *data)
{
struct curl_slist *last;
struct curl_slist *new_item;
DEBUGASSERT(data);
new_item = malloc(sizeof(struct curl_slist));
if(!new_item)
return NULL;
new_item->next = NULL;
new_item->data = data;
/* if this is the first item, then new_item *is* the list */
if(!list)
return new_item;
last = slist_get_last(list);
last->next = new_item;
return list;
}
/*
* curl_slist_append() appends a string to the linked list. It always returns
* the address of the first record, so that you can use this function as an
* initialization function as well as an append function. If you find this
* bothersome, then simply create a separate _init function and call it
* appropriately from within the program.
*/
struct curl_slist *curl_slist_append(struct curl_slist *list,
const char *data)
{
char *dupdata = strdup(data);
if(!dupdata)
return NULL;
list = Curl_slist_append_nodup(list, dupdata);
if(!list)
free(dupdata);
return list;
}
/*
* Curl_slist_duplicate() duplicates a linked list. It always returns the
* address of the first record of the cloned list or NULL in case of an
* error (or if the input list was NULL).
*/
struct curl_slist *Curl_slist_duplicate(struct curl_slist *inlist)
{
struct curl_slist *outlist = NULL;
struct curl_slist *tmp;
while(inlist) {
tmp = curl_slist_append(outlist, inlist->data);
if(!tmp) {
curl_slist_free_all(outlist);
return NULL;
}
outlist = tmp;
inlist = inlist->next;
}
return outlist;
}
/* be nice and clean up resources */
void curl_slist_free_all(struct curl_slist *list)
{
struct curl_slist *next;
struct curl_slist *item;
if(!list)
return;
item = list;
do {
next = item->next;
Curl_safefree(item->data);
free(item);
item = next;
} while(next);
}