getting an error msg while using file_get_contents()

Question

I am getting an warning messsage like this

Warning: file_get_contents() [function.file-get-contents]: stream does not support seeking

this is the code

$f=file_get_contents('https://api.facebook.com/method/stream.publish?message='.$facebook_message1[0].'%20'.$facebook_message1[1].'%20'.$facebook_message1[2].'%20'.$facebook_message1[3].'%20'.$facebook_message1[4].'%20'.$facebook_message1[5].'%20'.$facebook_message1[6].'%20'.$facebook_message1[7].'%20'.$facebook_message1[8].'%20'.$facebook_message1[9].'%20'.$facebook_message1[10].'%20'.$facebook_message1[11].'%20'.$facebook_message1[12].'%20'.$facebook_message1[13].'%20'.$facebook_message1[14].'%20'.$facebook_message1[15].'%20'.$facebook_message1[16].'%20'.$facebook_message1[17].'%20'.$facebook_message1[18].'%20'.$facebook_message1[19].'%20'.$facebook_message1[20].'&attachment={"name":"'.$url.'","href":"'.$url.'","caption":"","description":"","media":[{"type":"image","src":"'.$facebook_image.'","href":"'.$cat.'"}]}&uid='.$user_id.'&access_token='.$access_token.'', NULL, NULL, 246);

$fID = substr_replace($f,"",-27);

Answer 1

Your immediate problem is that you are using the fourth parameter of file_get_contents. You should simply omit that and cut off the relevant part of $f with substr later, like this:

$f = substr($f, 246);

However, there are many other issues:

1. The handling of $facebook_message is atrocious. Save your sanity and use implode('%20', $facebook_message) instead of the manual string concatenation.
2. It's a really bad idea to use the magic numbers 246 and -27 in your code. How did you produce these values? Obviously they refer to a part of the result string delimited by something, so document that by writing code that finds the delimiters. Your current code will break the moment facebook does any small change to their return value format, even if that change is purely technical and makes no difference from a semantic point of view.

Answer 2

You've told file_get_contents to seek to offset 246 with that final argument - you cannot do this with HTTP urls. You'll have fetch the entire response, then use

$f = substr($f, 246);

to extract the portions from 246 onwards.