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      1 /***************************************************************************
      2  *                                  _   _ ____  _
      3  *  Project                     ___| | | |  _ \| |
      4  *                             / __| | | | |_) | |
      5  *                            | (__| |_| |  _ <| |___
      6  *                             \___|\___/|_| \_\_____|
      7  *
      8  * Copyright (C) 1998 - 2013, Daniel Stenberg, <daniel (at) 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 http://curl.haxx.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 "slist.h"
     26 
     27 /* The last #include files should be: */
     28 #include "curl_memory.h"
     29 #include "memdebug.h"
     30 
     31 /* returns last node in linked list */
     32 static struct curl_slist *slist_get_last(struct curl_slist *list)
     33 {
     34   struct curl_slist     *item;
     35 
     36   /* if caller passed us a NULL, return now */
     37   if(!list)
     38     return NULL;
     39 
     40   /* loop through to find the last item */
     41   item = list;
     42   while(item->next) {
     43     item = item->next;
     44   }
     45   return item;
     46 }
     47 
     48 /*
     49  * Curl_slist_append_nodup() appends a string to the linked list. Rather than
     50  * copying the string in dynamic storage, it takes its ownership. The string
     51  * should have been malloc()ated. Curl_slist_append_nodup always returns
     52  * the address of the first record, so that you can use this function as an
     53  * initialization function as well as an append function.
     54  * If an error occurs, NULL is returned and the string argument is NOT
     55  * released.
     56  */
     57 struct curl_slist *Curl_slist_append_nodup(struct curl_slist *list, char *data)
     58 {
     59   struct curl_slist     *last;
     60   struct curl_slist     *new_item;
     61 
     62   DEBUGASSERT(data);
     63 
     64   new_item = malloc(sizeof(struct curl_slist));
     65   if(!new_item)
     66     return NULL;
     67 
     68   new_item->next = NULL;
     69   new_item->data = data;
     70 
     71   /* if this is the first item, then new_item *is* the list */
     72   if(!list)
     73     return new_item;
     74 
     75   last = slist_get_last(list);
     76   last->next = new_item;
     77   return list;
     78 }
     79 
     80 /*
     81  * curl_slist_append() appends a string to the linked list. It always returns
     82  * the address of the first record, so that you can use this function as an
     83  * initialization function as well as an append function. If you find this
     84  * bothersome, then simply create a separate _init function and call it
     85  * appropriately from within the program.
     86  */
     87 struct curl_slist *curl_slist_append(struct curl_slist *list,
     88                                      const char *data)
     89 {
     90   char *dupdata = strdup(data);
     91 
     92   if(!dupdata)
     93     return NULL;
     94 
     95   list = Curl_slist_append_nodup(list, dupdata);
     96   if(!list)
     97     free(dupdata);
     98 
     99   return list;
    100 }
    101 
    102 /*
    103  * Curl_slist_duplicate() duplicates a linked list. It always returns the
    104  * address of the first record of the cloned list or NULL in case of an
    105  * error (or if the input list was NULL).
    106  */
    107 struct curl_slist *Curl_slist_duplicate(struct curl_slist *inlist)
    108 {
    109   struct curl_slist *outlist = NULL;
    110   struct curl_slist *tmp;
    111 
    112   while(inlist) {
    113     tmp = curl_slist_append(outlist, inlist->data);
    114 
    115     if(!tmp) {
    116       curl_slist_free_all(outlist);
    117       return NULL;
    118     }
    119 
    120     outlist = tmp;
    121     inlist = inlist->next;
    122   }
    123   return outlist;
    124 }
    125 
    126 /* be nice and clean up resources */
    127 void curl_slist_free_all(struct curl_slist *list)
    128 {
    129   struct curl_slist     *next;
    130   struct curl_slist     *item;
    131 
    132   if(!list)
    133     return;
    134 
    135   item = list;
    136   do {
    137     next = item->next;
    138     Curl_safefree(item->data);
    139     free(item);
    140     item = next;
    141   } while(next);
    142 }
    143 
    144