Undefined index: transfer_encoding - php

Question

Ok a few weeks ago my script stopped working and today I notice I'm getting an error: [05-Mar-2017 06:31:32 America/Denver] PHP Notice: Undefined index: transfer_encoding in /home2/website/public_html/maps_apps/EasyWebFetch.php on line 105.
Here is what line 105 is:
if ($this->_resp_headers['transfer_encoding'] == 'chunked') {
Can someone point me in the right direction on getting this fixed?
Here is the main code:
<?php
require_once '/home2/website/public_html/maps_apps/EasyWebFetch.php';
$callback = isset($_GET['callback']) ? $_GET['callback'] : 'mymap.weatherhandler';
$station = isset($_GET['rid']) ? $_GET['rid'] : 'FWS';
$product = isset($_GET['product']) ? $_GET['product'] : 'NCR';
$nframes = isset($_GET['frames']) ? $_GET['frames'] : 10;
if (strlen($product) != 3 || strlen($station) != 3) { exit; }
// fetch directory listing
$wf = new EasyWebFetch;
if (!$wf->get("https://radar.weather.gov/ridge/RadarImg/$product/$station/")) {
print $wf->getErrorMessage();
exit;
}
$page = $wf->getContents();
echo $page."\n\n";
$size = preg_match_all( "/href=\"({$station}[\d_]+{$product}\.gif)\"/" , $page, $match);
$files = $match[1];
if ($nframes == 'all') { $nframes = count($files); }
$nframes = min(count($files), $nframes);
$files = array_slice($files, -$nframes);
echo $callback."\n(\n{\ndirectory:\n[\n";
for ($i=0; $i < $nframes; $i++) {
echo "\"ridge/RadarImg/$product/$station/$files[$i]\",\n";
}
echo "]\n}\n)\n;"
?>
and here is EasyWebFetch.php
<?php
/*
* EasyWebFetch - Fetch a page by opening socket connection, no dependencies
*
* PHP version 5
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
* #author Nashruddin Amin <me#nashruddin.com>
* #copyright Nashruddin Amin 2008
* #license GNU General Public License 3.0
* #package EasyWebFetch
* #version 1.1
*/
class EasyWebFetch
{
private $_request_url;
private $_host;
private $_path;
private $_query;
private $_fragment;
private $_headers_only;
private $_portnum = 80;
private $_user_agent = "SimpleHttpClient/3.0";
private $_req_timeout = 30;
private $_maxredirs = 5;
private $_use_proxy = false;
private $_proxy_host;
private $_proxy_port;
private $_proxy_user;
private $_proxy_pass;
private $_status;
private $_resp_headers;
private $_resp_body;
private $_is_error;
private $_errmsg;
/**
* class constructor
*/
public function __construct()
{
$this->_resp_headers = array();
$this->_resp_body = "";
}
/**
* get the requested page
*
* #param string $url URL of the requested page
* #param boolean $headers_only true to return headers only,
* false to return headers and body
*
* #return boolean true on success, false on failure
*/
public function get($url = '', $headers_only = false)
{
$this->_request_url = $url;
$this->_headers_only = $headers_only;
$redir = 0;
while(($redir++) <= $this->_maxredirs) {
$this->parseUrl($this->_request_url);
if (($response = $this->makeRequest()) == false) {
return(false);
}
/* split head and body */
$neck = strpos($response, "\r\n\r\n");
$head = substr($response, 0, $neck);
$body = substr($response, $neck+2);
/* read response headers */
$this->_resp_headers = $this->parseHeaders($head);
/* check for redirects */
if ($this->getStatus() == 301 || $this->getStatus() == 302) {
$follow = $this->_resp_headers['location'];
$this->_request_url = $this->setFullPath($follow, $this->_request_url);
continue;
} else {
/* no redirects, start reading response body */
break;
}
}
/* read the body part */
if ($this->_resp_headers['transfer_encoding'] == 'chunked') {
$this->_resp_body = $this->joinChunks($body);
} else {
$this->_resp_body = $body;
}
return(true);
}
/**
* build HTTP header and perform HTTP request
*
* #return mixed HTTP response on success, false on failure
*/
private function makeRequest()
{
$method = ($this->_headers_only == true) ? "HEAD" : "GET";
$proxy_auth = base64_encode("$this->_proxy_user:$this->_proxy_pass");
$response = "";
if ($this->_use_proxy) {
$headers = "$method $this->_request_url HTTP/1.1\r\n"
. "Host: $this->_host\r\n"
. "Proxy-Authorization: Basic $proxy_auth\r\n"
. "User-Agent: $this->_user_agent\r\n"
. "Connection: Close\r\n\r\n";
$fp = fsockopen($this->_proxy_host, $this->_proxy_port, $errno, $errmsg, $this->_req_timeout);
} else {
$headers = "$method $this->_path$this->_query$this->_fragment HTTP/1.1\r\n"
. "Host: $this->_host\r\n"
. "User-Agent: $this->_user_agent\r\n"
. "Connection: Close\r\n\r\n";
$fp = fsockopen($this->_host, $this->_portnum, $errno, $errmsg, $this->_req_timeout);
}
if (!$fp) {
$this->_is_error = true;
$this->_errmsg = "Unknown error";
return(false);
}
fwrite($fp, $headers);
while(!feof($fp)) {
$response .= fgets($fp, 4096);
}
fclose($fp);
return($response);
}
/**
* parse the requested URL to its host, path, query and fragment
*
* #return void
*/
private function parseUrl($url)
{
$this->_host = parse_url($url, PHP_URL_HOST);
$this->_path = parse_url($url, PHP_URL_PATH);
$this->_query = parse_url($url, PHP_URL_QUERY);
$this->_fragment = parse_url($url, PHP_URL_FRAGMENT);
if (empty($this->_path)) {
$this->_path = '/';
}
}
/**
* get the full path of the page to redirect. if the requested page is
* http://www.example.com and it redirects to redirpage.html, then the
* new request is http://www.example.com/redirpage.html
*
* #param string $loc new location from the HTTP response headers
* #param string $parent_url the parent's URL
*
* #return string full path of the page to redirect
*/
private function setFullPath($loc, $parent_url)
{
$parent_url = preg_replace("/\/[^\/]*$/", "", $parent_url);
if (strpos($loc, 'http://') !== false) {
return($loc);
}
if (strpos($loc, '../') === false) {
return("$parent_url/$loc");
}
while (strpos($loc, '../') !== false) {
$loc = preg_replace("/^\.\.\//", "", $loc);
$parent_url = preg_replace("/\/[^\/]+$/", "", $parent_url);
}
return("$parent_url/$loc");
}
/**
* parse HTTP response headers to array
*
* #param string $string HTTP response headers
*
* #return array
*/
private function parseHeaders($string)
{
$string = trim($string);
$headers = array();
$lines = explode("\r\n", $string);
$headers['http_status'] = $lines[0];
/* read HTTP _status in first line */
preg_match('/HTTP\/(\\d\\.\\d)\\s*(\\d+)\\s*(.*)/', $lines[0], $m);
$this->_status = $m[2];
array_splice($lines, 0, 1); /* remove first line */
foreach ($lines as $line) {
list($key, $val) = explode(': ', $line);
$key = str_replace("-", "_", $key);
$key = strtolower($key);
$val = trim($val);
$headers[$key] = $val;
}
return($headers);
}
/**
* join parts of the HTTP response body with chunked transfer-encoding
*
* #param string $chunks HTTP response body
*
* #return string full body
*/
private function joinChunks($chunks)
{
preg_match("/\r\n([0-9a-z]+)(;?.*)\r\n/", $chunks, $match);
$size = hexdec($match[1]);
$body = "";
while($size > 0) {
/* remove line with chunk size */
$chunks = preg_replace("/\r\n.+\r\n/m", "", $chunks, 1);
$part = substr($chunks, 0, $size);
$chunks = substr($chunks, $size);
$body .= $part;
/* get next chunk size */
preg_match("/\r\n([0-9a-z]+)(;?.*)\r\n/", $chunks, $match);
$size = hexdec($match[1]);
}
return($body);
}
/**
* set the requested URL
*
* #param string $url URL of the requested page
*/
public function setRequestUrl($url)
{
$this->_request_url = $url;
}
/**
* set to return headers only
*
* #param boolean $headers_only true to return headers only,
* false to return headers and body
*/
public function returnHeadersOnly($headers_only)
{
$this->_headers_only = $headers_only;
}
/**
* set proxy host and port
*
* #param string $hostport proxy host and proxy port in format proxy_host:proxy_port
*/
public function setProxyHost($hostport)
{
list($this->_proxy_host, $this->_proxy_port) = explode(':', $hostport);
$this->_use_proxy = true;
}
/**
* set proxy user and password
*
* #param string $userpass proxy user and password in format proxy_user:proxy_password
*/
public function setProxyUser($userpass)
{
list($this->_proxy_user, $this->_proxy_pass) = explode(':', $userpass);
}
/**
* get the HTTP response status (200, 404, etc)
*
* #return string
*/
public function getStatus()
{
return($this->_status);
}
/**
* get the requested URL
*
* #return string
*/
public function getRequestUrl()
{
return($this->_request_url);
}
/**
* set maximum redirects
*
* #param int $maxredirs
*/
public function setMaxRedirs($maxredirs)
{
$this->_maxredirs = $maxredirs;
}
/**
* get HTTP response headers
*
* #return array
*/
public function getHeaders()
{
return($this->_resp_headers);
}
/**
* get the HTTP response body, usually in HTML
*
* #return string
*/
public function getContents()
{
return($this->_resp_body);
echo $this->_resp_body;
}
/**
* get error message
*
* #return string
*/
public function getErrorMessage()
{
return($this->_errmsg);
}
/**
* print debug information
*/
private function debug($text)
{
print "$text\n";
}
}
?>

Answer 1

The array _resp_headers doesn't have any element with key transfer_encoding.
To fix the notice, you should check if the array has the key transfer_encoding:
if (array_key_exists('transfer_encoding', $this->_resp_headers) && $this->_resp_headers['transfer_encoding'] == 'chunked') {
But I can't tell you why the key is not set and why the script has stopped working if you don't show more code.

Answer 2

difficult to answer with such a small sample of code but you can check for the index's existence before
if (isset($this->_resp_headers['transfer_encoding']) &&
$this->_resp_headers['transfer_encoding'] == 'chunked') {