curl-w32/docs/libcurl/curl_slist_append.md

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---
c: Copyright (C) Daniel Stenberg, <daniel.se>, et al.
SPDX-License-Identifier: curl
Title: curl_slist_append
Section: 3
Source: libcurl
See-also:
- curl_slist_free_all (3)
---
# NAME
curl_slist_append - add a string to an slist
# SYNOPSIS
~~~c
#include <curl/curl.h>
struct curl_slist *curl_slist_append(struct curl_slist *list,
const char *string);
~~~
# DESCRIPTION
curl_slist_append(3) appends a string to a linked list of strings. The
existing **list** should be passed as the first argument and the new list is
returned from this function. Pass in NULL in the **list** argument to create
a new list. The specified **string** has been appended when this function
returns. curl_slist_append(3) copies the string.
The list should be freed again (after usage) with
curl_slist_free_all(3).
# EXAMPLE
~~~c
int main(void)
{
CURL *handle;
struct curl_slist *slist = NULL;
struct curl_slist *temp = NULL;
slist = curl_slist_append(slist, "pragma:");
if(!slist)
return -1;
temp = curl_slist_append(slist, "Accept:");
if(!temp) {
curl_slist_free_all(slist);
return -1;
}
slist = temp;
curl_easy_setopt(handle, CURLOPT_HTTPHEADER, slist);
curl_easy_perform(handle);
curl_slist_free_all(slist); /* free the list again */
}
~~~
# AVAILABILITY
Always
# RETURN VALUE
A null pointer is returned if anything went wrong, otherwise the new list
pointer is returned. To avoid overwriting an existing non-empty list on
failure, the new list should be returned to a temporary variable which can
be tested for NULL before updating the original list pointer.