curl/docs/libcurl/curl_slist_append.3

.\" **************************************************************************
.\" *                                  _   _ ____  _
.\" *  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.
.\" *
.\" **************************************************************************
.TH curl_slist_append 3 "19 Jun 2003" "libcurl 7.10.4" "libcurl Manual"
.SH NAME
curl_slist_append - add a string to an slist
.SH SYNOPSIS
.B #include <curl/curl.h>
.sp
.BI "struct curl_slist *curl_slist_append(struct curl_slist *" list,
.BI "const char * "string ");"
.ad
.SH DESCRIPTION
\fIcurl_slist_append(3)\fP appends a string to a linked list of strings. The
existing \fBlist\fP should be passed as the first argument and the new list is
returned from this function. Pass in NULL in the \fBlist\fP argument to create
a new list. The specified \fBstring\fP has been appended when this function
returns. \fIcurl_slist_append(3)\fP copies the string.

The list should be freed again (after usage) with
\fIcurl_slist_free_all(3)\fP.
.SH 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.
.SH EXAMPLE
.nf
CURL *handle;
struct curl_slist *slist=NULL;
struct curl_slist *temp=NULL;

slist = curl_slist_append(slist, "pragma:");

if (slist == NULL)
  return -1;

temp = curl_slist_append(slist, "Accept:")

if (temp == NULL) {
  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 */
.fi
.SH "SEE ALSO"
.BR curl_slist_free_all "(3), "