1--- 2c: Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al. 3SPDX-License-Identifier: curl 4Title: curl_slist_append 5Section: 3 6Source: libcurl 7See-also: 8 - curl_slist_free_all (3) 9Protocol: 10 - All 11Added-in: 7.1 12--- 13 14# NAME 15 16curl_slist_append - add a string to an slist 17 18# SYNOPSIS 19 20~~~c 21#include <curl/curl.h> 22 23struct curl_slist *curl_slist_append(struct curl_slist *list, 24 const char *string); 25~~~ 26 27# DESCRIPTION 28 29curl_slist_append(3) appends a string to a linked list of strings. The 30existing **list** should be passed as the first argument and the new list is 31returned from this function. Pass in NULL in the **list** argument to create 32a new list. The specified **string** has been appended when this function 33returns. curl_slist_append(3) copies the string. 34 35The list should be freed again (after usage) with 36curl_slist_free_all(3). 37 38# %PROTOCOLS% 39 40# EXAMPLE 41 42~~~c 43int main(void) 44{ 45 CURL *handle; 46 struct curl_slist *slist = NULL; 47 struct curl_slist *temp = NULL; 48 49 slist = curl_slist_append(slist, "pragma:"); 50 51 if(!slist) 52 return -1; 53 54 temp = curl_slist_append(slist, "Accept:"); 55 56 if(!temp) { 57 curl_slist_free_all(slist); 58 return -1; 59 } 60 61 slist = temp; 62 63 curl_easy_setopt(handle, CURLOPT_HTTPHEADER, slist); 64 65 curl_easy_perform(handle); 66 67 curl_slist_free_all(slist); /* free the list again */ 68} 69~~~ 70 71# %AVAILABILITY% 72 73# RETURN VALUE 74 75A null pointer is returned if anything went wrong, otherwise the new list 76pointer is returned. To avoid overwriting an existing non-empty list on 77failure, the new list should be returned to a temporary variable which can 78be tested for NULL before updating the original list pointer. 79