Webpage update notification

[suman haldar]

Dear Friends,

I want to write PHP script which will use fsockopen to connect to a webpage. and it will check whether the content is changed. If the content is changed it will send a notification to an email address.
Now the first part.

opening a socket connection to a webpage and then returning the file pointer.

and last sending the notification email using the mail function is much clear to me.

But How can I can I check the content. Where the page is changed. And What is the change. There I am stuck. I am weak in the regular expression part.

Wish some guru here can help me out on this case.

Thanks in advance.

Suman Haldar

[jatar_k]

Welcome to WebmasterWorld suman haldar,

try this page, the user comments have exactly what you are looking for

[php.net...]

[suman haldar]

Dear jatar_k,

I have gone through the document. Which time it will return the remote server time. Or the time in my server where i m running my script?
Is there any way to determine what is the server time of the remote system?

[jatar_k]

the third comment down says it will return the last modified time of the file and has a function someone wrote to do it

[suman haldar]

The third Example

<?php
function filemtime_remote($uri)
{
  $uri = parse_url($uri);
  $handle = @fsockopen($uri['host'],80);
  if(!$handle)
    return 0;
  fputs($handle,"GET $uri[path] HTTP/1.1\r\nHost: $uri[host]\r\n\r\n");
  $result = 0;
  while(!feof($handle))
  {
    $line = fgets($handle,1024);
    if(!trim($line))
      break;
    $col = strpos($line,':');
    if($col!== false)
    {
      $header = trim(substr($line,0,$col));
      $value = trim(substr($line,$col+1));
      if(strtolower($header) == 'last-modified')
      {
        $result = strtotime($value);
        break;
      }
    }
  }
  fclose($handle);
  return $result;
}
echo filemtime_remote('http://example.example.com/index.php');
?>

They said the function will return the last modification date of a JPG file. But in my case it is always returning a 0. Do you have any idea why?