Check if a URL exists.

**Eric** · 04-11-2007, 12:52 PM

Howdy.

This simple function will check if a url is valid (going by parse_url()) and if it's 'online' - by seeing if it returns a 302, 301, or 200 status code.

EDIT: 3/4/2008, updated to more efficient.

PHP Code:

  <?php

 
function is_valid_url($url)

{

    $url = @parse_url($url);

????: NamePros.com http://www.namepros.com/code/315565-check-if-a-url-exists.html
 
    if (!$url)

    {

        return false;

    }

 
    $url = array_map('trim', $url);

    $url['port'] = (!isset($url['port'])) ? 80 : (int)$url['port'];

 
    $path = (isset($url['path'])) ? $url['path'] : '/';

    $path .= (isset($url['query'])) ? "?$url[query]" : '';

 
    if (isset($url['host']) AND $url['host'] != gethostbyname($url['host']))

????: NamePros.com http://www.namepros.com/showthread.php?t=315565
    {

        if (PHP_VERSION >= 5)

        {

            $headers = implode('', get_headers("$url[scheme]://$url[host]:$url[port]$path"));

        }

        else

        {

            $fp = fsockopen($url['host'], $url['port'], $errno, $errstr, 30);

 
            if (!$fp)

            {

                return false;

            }

            fputs($fp, "HEAD $path HTTP/1.1\r\nHost: $url[host]\r\n\r\n");

            $headers = fread($fp, 4096);

            fclose($fp);

        }

        return (bool)preg_match('#^HTTP/.*\s+[(200|301|302)]+\s#i', $headers);

    }

    return false;

}

 
?>

bobby9101 · 04-15-2007, 05:04 PM

I needed this a little while ago, and here is what I have:

PHP Code:

  function url_exists($url) {

@ $headers = get_headers($url);

    return preg_match('/^HTTP\/\d\.\d\s+(200|301|302)/', $headers[0]);

????: NamePros.com http://www.namepros.com/showthread.php?t=315565
}

then use:
if ($headers[0] == 1) {
code
}

**Eric** · 04-15-2007, 05:17 PM

Originally Posted by bobby9101

I needed this a little while ago, and here is what I have:

PHP Code:

  function url_exists($url) {

????: NamePros.com http://www.namepros.com/showthread.php?t=315565
@ $headers = get_headers($url);

    return preg_match('/^HTTP\/\d\.\d\s+(200|301|302)/', $headers[0]);

}

then use:
if ($headers[0] == 1) {
code
}

Not everyone has PHP5

**Eric** · 03-04-2008, 05:28 PM

Updated the code, check first post.

abcde · 04-10-2008, 05:26 AM

Originally Posted by SecondVersion

Updated the code, check first post.

I don't get it, how to use that code above? sorry, im a newbie with php

RageD · 04-10-2008, 04:49 PM

Originally Posted by abcde

I don't get it, how to use that code above? sorry, im a newbie with php

First, you need a webhost which supports PHP or to install it on your own PC. But on your own PC you need to also install a webserver and it's a real hassle so it's easier to have a webhost with this.
????: NamePros.com http://www.namepros.com/showthread.php?t=315565

Then, input this script in to a file called file.php (or whatever_you_want.php) and save and close the file.

Now in SecondVersion's script he created the function called $is_valid_url($url); so what you'll want to do to see if a URL exists: (within the same file that the function is in [or if it's included for that matter])

PHP Code:

  <?php

// Test script. Function created by SecondVersion

function is_valid_url($url)

{

    $url = @parse_url($url);

 
    if (!$url)

    {

        return false;

    }

 
    $url = array_map('trim', $url);

    $url['port'] = (!isset($url['port'])) ? 80 : (int)$url['port'];

 
    $path = (isset($url['path'])) ? $url['path'] : '/';

    $path .= (isset($url['query'])) ? "?$url[query]" : '';

 
    if (isset($url['host']) AND $url['host'] != gethostbyname($url['host']))

    {

        if (PHP_VERSION >= 5)

        {

            $headers = implode('', get_headers("$url[scheme]://$url[host]:$url[port]$path"));

        }

        else

        {

            $fp = fsockopen($url['host'], $url['port'], $errno, $errstr, 30);

 
            if (!$fp)

            {

                return false;

????: NamePros.com http://www.namepros.com/showthread.php?t=315565
            }

            fputs($fp, "HEAD $path HTTP/1.1\r\nHost: $url[host]\r\n\r\n");

            $headers = fread($fp, 4096);

            fclose($fp);

        }

        return (bool)preg_match('#^HTTP/.*\s+[(200|301|302)]+\s#i', $headers);

    }

    return false;

}

 
if(is_valid_url("http://namepros.com"))

{

    echo("w00t for Namepros.com! It's alive!");

}else{

    echo("Oh no! Where did NamePros go!?! :(");

}

 
?>

-RageD

**Eric** · 04-17-2008, 05:11 AM

Thanks for answering that for me, RageD.

itnashvillecom · 06-30-2008, 07:42 PM

why not just:

$var = file_get_contents($url);
if ($var == TRUE) {
// url is ok
} else {
// url is invalid
}

**Eric** · 06-30-2008, 08:31 PM

Originally Posted by itnashvillecom

why not just:

$var = file_get_contents($url);
if ($var == TRUE) {
// url is ok
} else {
// url is invalid
????: NamePros.com http://www.namepros.com/showthread.php?t=315565
}

What would be the point of getting the URL's content? That'd be useless and inefficient. This function does the same without the burden of gathering content.

itnashvillecom · 07-11-2008, 10:33 PM

Just set max length to 1 to keep from grabbing the whole thing.. Beats using a gigantic function, overkill to me. Much less processing time and lower load.

04-11-2007, 12:52 PM	THREAD STARTER #1 (permalink)
Eric Tech Support Join Date: Mar 2005 Posts: 4,944	Check if a URL exists. Howdy. This simple function will check if a url is valid (going by parse_url()) and if it's 'online' - by seeing if it returns a 302, 301, or 200 status code. EDIT: 3/4/2008, updated to more efficient. PHP Code: <?php function is_valid_url($url) { $url = @parse_url($url); ????: NamePros.com http://www.namepros.com/code/315565-check-if-a-url-exists.html if (!$url) { return false; } $url = array_map('trim', $url); $url['port'] = (!isset($url['port'])) ? 80 : (int)$url['port']; $path = (isset($url['path'])) ? $url['path'] : '/'; $path .= (isset($url['query'])) ? "?$url[query]" : ''; if (isset($url['host']) AND $url['host'] != gethostbyname($url['host'])) ????: NamePros.com http://www.namepros.com/showthread.php?t=315565 { if (PHP_VERSION >= 5) { $headers = implode('', get_headers("$url[scheme]://$url[host]:$url[port]$path")); } else { $fp = fsockopen($url['host'], $url['port'], $errno, $errstr, 30); if (!$fp) { return false; } fputs($fp, "HEAD $path HTTP/1.1\r\nHost: $url[host]\r\n\r\n"); $headers = fread($fp, 4096); fclose($fp); } return (bool)preg_match('#^HTTP/.\s+[(200\|301\|302)]+\s#i', $headers); } return false; } ?> Last edited by SecondVersion; 03-04-2008 at 05:29 PM.*

04-15-2007, 05:04 PM	#2 (permalink)
bobby9101 Senior Member Join Date: Jun 2005 Posts: 1,478	I needed this a little while ago, and here is what I have: PHP Code: `function url_exists($url) { @ $headers = get_headers($url); return preg_match('/^HTTP\/\d\.\d\s+(200\|301\|302)/', $headers[0]); ????: NamePros.com http://www.namepros.com/showthread.php?t=315565 }` then use: if ($headers[0] == 1) { code }

07-11-2008, 10:33 PM	#10 (permalink)
itnashvillecom Account Suspended Join Date: Jun 2008 Posts: 156	Just set max length to 1 to keep from grabbing the whole thing.. Beats using a gigantic function, overkill to me. Much less processing time and lower load. Last edited by itnashvillecom; 07-11-2008 at 10:37 PM.

03-04-2008, 05:28 PM	THREAD STARTER #4 (permalink)
Eric Tech Support Join Date: Mar 2005 Posts: 4,944	Updated the code, check first post.

04-17-2008, 05:11 AM	THREAD STARTER #7 (permalink)
Eric Tech Support Join Date: Mar 2005 Posts: 4,944	Thanks for answering that for me, RageD.

06-30-2008, 07:42 PM	#8 (permalink)
itnashvillecom Account Suspended Join Date: Jun 2008 Posts: 156	why not just: $var = file_get_contents($url); if ($var == TRUE) { // url is ok } else { // url is invalid }

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