How can I test for a serialized variable? Without throwing E_NOTICE if string is not serialized

Question

I am coding my own var_dump to meet certain requirements which probably only apply to me and have a problem.

The code checks for objects, arrays, etc and finally gets to a stage where it reckons it is left with a number, a string or a boolean.

Of course, a string can actually be a serialized variable, so I want to heck for that ...

if (is_string($variable))
{
   // check if it is serialzed; if so, unserialize & dump as an array, \
   // with a suitable header indicating that it was serialized
   try
   {
      $old_error_level= error_reporting(E_ALL ^ E_NOTICE);
      $unserialized_varaible = @unserialize($variable);
      $result .= my_dump($unserialized_varaible, ... <some params>); // recursive call
      $old_error_level= error_reporting($old_error_level);
   }

   catch(Exception $e)    // Treat it as a string
   {
       $old_error_level= error_reporting($old_error_level);
       $result .= GetHtmlForSimpleVariable($variable, ... <some params>);
   }
}

But, what I get when trying to dump a simple, non-serialized, string is

Problem type Notice "unserialize() 
  [<a href='function.unserialize'>function.unserialize</a>]:
  Error at offset 0 of 14 bytes" at line 362 in file my_dump.php<br><br>

Update: the point there is that I want to suppress that E_NOTICE when a string is not a serialized string. I had thought that the @on @unserizlize() would do that, but ...

If the string is serialized then everything is hunky dory. If not, then not.

That's an error in the function `my_dump`, isn't it? `unserialize` seems to be working, no? Else, where is line 362, is that the line you call `unserialize` on? — deceze, Aug 30 '11 at 04:07
sorry about that. Yes, unserialzie works correctly on serialized strings, but gives a Notice when not serialized. — Mawg says reinstate Monica, Aug 30 '11 at 04:17
It should work perfectly fine without notice since you're silencing any errors using `@`. Are you by chance using an extension that disables `@`? — deceze, Aug 30 '11 at 04:28
I guess http://stackoverflow.com/questions/1369936/check-to-see-if-a-string-is-serialized/1369946#1369946 answer will help you. — Hari K T, Aug 30 '11 at 04:46
Plus 1, @Hari, I already saw that question. Just can't figure why mine is throwing a NOTICE — Mawg says reinstate Monica, Aug 30 '11 at 09:37

profitphp · Accepted Answer · 2011-08-30T04:21:03.477

3

When you try to unserialize it, it returns false if it is not serialized. It also returns a an E_NOTICE which is where that output is coming from.

From the manual:

In case the passed string is not unserializeable, FALSE is returned and E_NOTICE is issued.

Check if the return value of unserialize ===false

edited Aug 30 '11 at 04:21

answered Aug 30 '11 at 04:15

profitphp

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Sorry, it looks like I need to update the question. That's the whole point of it; if the string is not serialized an E_NOTICE is thrown which I want to suppress. – Mawg says reinstate Monica Aug 30 '11 at 04:18
1

Ya, partly my fault as well, I kinda just answered the title and beginning summary of the question rather than looking at all the code. – profitphp Aug 30 '11 at 04:22
1

@mawg It looks like you are calling unserialize somewhere else and perhaps that one is missing the @ – profitphp Aug 30 '11 at 04:31
+1 for your answer and +1 for each of your comments. Certainly not your fault. I definitely gave the wrong title to the question :-( and that is the only unserialize() in the entire code ... (besides which, Xdebug dumps the stack, so I can be sure of it) – Mawg says reinstate Monica Aug 30 '11 at 09:39
Nvm. I'll award you teh answer & keep looking – Mawg says reinstate Monica Aug 31 '11 at 13:51

How can I test for a serialized variable? Without throwing E_NOTICE if string is not serialized

1 Answers1