Blog : How can I check if a URL exists via PHP?
How can I check if a URL exists via PHP?
$file = 'http://www.domain.com/somefile.jpg';
$file_headers = @get_headers($file);
if($file_headers[0] == 'HTTP/1.1 404 Not Found') {
$exists = false;
}
else {
$exists = true;
}
From here: http://www.php.net/manual/en/function.file-exists.php#75064
...and right below the above post, there's a curl solution:
function url_exists($url) {
if (!$fp = curl_init($url)) return false;
return true;
}
$headers = @get_headers($this->_value);
if(strpos($headers[0],'200')===false)return false;
so anytime you contact a website and get something else than 200 ok it will work
there are a few things to pay attention to:
• is the url actually valid (a string, not empty, good syntax), this is quick to check server side
• waiting for a response might take time and block code execution
• not all headers returned by get_headers() are well formed
• use curl if you can
• prevent fetching the entire body/content, but only request the headers
• consider redirecting urls:
• do you want the first code returned?
• or follow all redirects and return the last code?
• you might end up with a 200, but it could redirect using javascript... we'll never know what happens after
Keep in mind that whatever method you use, it takes time to wait for a response. All code might (and probably will) halt untill you either know the result or the requests have timed out.
for example: the code below could take a LONG time to display the page if the urls are invalid or unreachable:
$urls = getUrls(); // some function getting say 10 or more external links
foreach($urls as $k=>$url){
// this could potentially take 0-30 seconds each
// (more or less depending on connection, target site, timeout settings...)
if( ! isValidUrl($url) ){
unset($urls[$k]);
}
}
echo "yay all done! now show my site";
foreach($urls as $url){
echo "
{$url}";
}
?>
the functions below could be helpfull, you probably want to modify them to suit your needs:
function isValidUrl($url){
// first do some quick sanity checks:
if(!$url || !is_string($url)){
return false;
}
// quick check url is roughly a valid http request: ( http://blah/... )
if( ! preg_match('/^http(s)?:\/\/[a-z0-9-]+(.[a-z0-9-]+)*(:[0-9]+)?(\/.*)?$/i', $url) ){
return false;
}
// the next bit could be slow:
if(getHttpResponseCode_using_curl($url) != 200){
// if(getHttpResponseCode_using_getheaders($url) != 200){ // use this one if you cant use curl
return false;
}
// all good!
return true;
}
function getHttpResponseCode_using_curl($url, $followredirects = true){
// returns int responsecode, or false (if url does not exist or connection timeout occurs)
// NOTE: could potentially take up to 0-30 seconds , blocking further code execution (more or less depending on connection, target site, and local timeout settings))
// if $followredirects == false: return the FIRST known httpcode (ignore redirects)
// if $followredirects == true : return the LAST known httpcode (when redirected)
if(! $url || ! is_string($url)){
return false;
}
$ch = @curl_init($url);
if($ch === false){
return false;
}
@curl_setopt($ch, CURLOPT_HEADER ,true); // we want headers
@curl_setopt($ch, CURLOPT_NOBODY ,true); // dont need body
@curl_setopt($ch, CURLOPT_RETURNTRANSFER ,true); // catch output (do NOT print!)
if($followredirects){
@curl_setopt($ch, CURLOPT_FOLLOWLOCATION ,true);
@curl_setopt($ch, CURLOPT_MAXREDIRS ,10); // fairly random number, but could prevent unwanted endless redirects with followlocation=true
}else{
@curl_setopt($ch, CURLOPT_FOLLOWLOCATION ,false);
}
// @curl_setopt($ch, CURLOPT_CONNECTTIMEOUT ,5); // fairly random number (seconds)... but could prevent waiting forever to get a result
// @curl_setopt($ch, CURLOPT_TIMEOUT ,6); // fairly random number (seconds)... but could prevent waiting forever to get a result
// @curl_setopt($ch, CURLOPT_USERAGENT ,"Mozilla/5.0 (Windows NT 6.0) AppleWebKit/537.1 (KHTML, like Gecko) Chrome/21.0.1180.89 Safari/537.1"); // pretend we're a regular browser
@curl_exec($ch);
if(@curl_errno($ch)){ // should be 0
@curl_close($ch);
return false;
}
$code = @curl_getinfo($ch, CURLINFO_HTTP_CODE); // note: php.net documentation shows this returns a string, but really it returns an int
@curl_close($ch);
return $code;
}
function getHttpResponseCode_using_getheaders($url, $followredirects = true){
// returns string responsecode, or false if no responsecode found in headers (or url does not exist)
// NOTE: could potentially take up to 0-30 seconds , blocking further code execution (more or less depending on connection, target site, and local timeout settings))
// if $followredirects == false: return the FIRST known httpcode (ignore redirects)
// if $followredirects == true : return the LAST known httpcode (when redirected)
if(! $url || ! is_string($url)){
return false;
}
$headers = @get_headers($url);
if($headers && is_array($headers)){
if($followredirects){
// we want the the last errorcode, reverse array so we start at the end:
$headers = array_reverse($headers);
}
foreach($headers as $hline){
// search for things like "HTTP/1.1 200 OK" , "HTTP/1.0 200 OK" , "HTTP/1.1 301 PERMANENTLY MOVED" , "HTTP/1.1 400 Not Found" , etc.
// note that the exact syntax/version/output differs, so there is some string magic involved here
if(preg_match('/^HTTP\/\S+\s+([1-9][0-9][0-9])\s+.*/', $hline, $matches) ){// "HTTP/*** ### ***"
$code = $matches[1];
return $code;
}
}
// no HTTP/xxx found in headers:
return false;
}
// no headers :
return false;
}
you cannot use curl in certain servers u can use this code
$url = 'http://www.example.com';
$array = get_headers($url);
$string = $array[0];
if(strpos($string,"200"))
{
echo 'url exists';
}
else
{
echo 'url does not exist';
}
?>
function URLIsValid($URL)
{
$exists = true;
$file_headers = @get_headers($URL);
$InvalidHeaders = array('404', '403', '500');
foreach($InvalidHeaders as $HeaderVal)
{
if(strstr($file_headers[0], $HeaderVal))
{
$exists = false;
break;
}
}
return $exists;
}
$url = 'http://google.com';
$not_url = 'stp://google.com';
if (@file_get_contents($url)): echo "Found '$url'!";
else: echo "Can't find '$url'.";
endif;
if (@file_get_contents($not_url)): echo "Found '$not_url!";
else: echo "Can't find '$not_url'.";
endif;
// Found 'http://google.com'!Can't find 'stp://google.com'.
pretty fast:
function http_response($url){
$resURL = curl_init();
curl_setopt($resURL, CURLOPT_URL, $url);
curl_setopt($resURL, CURLOPT_BINARYTRANSFER, 1);
curl_setopt($resURL, CURLOPT_HEADERFUNCTION, 'curlHeaderCallback');
curl_setopt($resURL, CURLOPT_FAILONERROR, 1);
curl_exec ($resURL);
$intReturnCode = curl_getinfo($resURL, CURLINFO_HTTP_CODE);
curl_close ($resURL);
if ($intReturnCode != 200 && $intReturnCode != 302 && $intReturnCode != 304) { return 0; } else return 1;
}
echo 'google:';
echo http_response('http://www.google.com');
echo '/ ogogle:';
echo http_response('http://www.ogogle.com');
function urlIsOk($url)
{
$headers = @get_headers($url);
$httpStatus = intval(substr($headers[0], 9, 3));
if ($httpStatus<400)
{
return true;
}
return false;
}
Try it, I'm using this, working very fine, my you also helpful, thanks.
$url = 'http://www.example.com';
$array = get_headers($url);
$string = $array[0];
if(strpos($string,"200")) {
echo 'url exists';
} else {
echo 'url does not exist';
}
the simple way is curl (and FASTER too)
$mylinks="http://site.com/page.html";
$handlerr = curl_init($mylinks);
curl_setopt($handlerr, CURLOPT_RETURNTRANSFER, TRUE);
$resp = curl_exec($handlerr);
$ht = curl_getinfo($handlerr, CURLINFO_HTTP_CODE);
if ($ht == '404')
{ echo 'OK';}
else { echo 'NO';}
?>