Notice: unserialize() [function.unserialize]: Error at offset 111 of 118 bytes in /home/maxwell4/public_html/main/wp-content/plugins/shopp/core/model/Settings.php on line 228

…she had done a ‘find and replace’ in a SQL DB dump to change her domain name, boogered it up accidentally, and needed an explanation. The answer I gave applies any time that error occurs in PHP, so i thought it was worth posting here!

Reason: Arrays are often serialized so that they can be stored in a database text field. If you change the data within a serialized array, without changing the character count, you will get the error above.

For example, try this:

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<?php
$thing = array('one','two');
echo serialize($thing);
?>

This will echo out the following: a:2:{i:0;s:3:”one”;i:1;s:3:”two”;}
Now… if you stored that in a database, you could then retrieve it later and unserialize() it to get your array back. wohoo!

In that serialized data, s:3:”one” means that the first element in the array is a string, and that it’s 3 characters long. Now.. if you manually changed “one” to “otherone” like this a:2:{i:0;s:3:”otherone”;i:1;s:3:”two”;} then when you ran it through unserialize() to retrieve your array, you would get the error were talking about.

Fix: To correct this you would need to update the string length also like so: a:2:{i:0;s:8:”otherone”;i:1;s:3:”two”;} because “otherone” is actually 8 characters long. See? Good!

Any questions, please leave a message below.

Fix: Turns out PHP flags can be called from .htaccess file. So assuming you are using Unix type hosting (or another server that can interpret distributed configuration files), you can add this to your .htaccess file to set the timezone:

php_value date.timezone Europe/London

Save that, upload it, and if you then look at the output of phpinfo() (create a php file with this in and upload it), you should see:

The Local Value should show what you set in the .htaccess file

Fix: Here’s a common line from class.phpmailer.php scripts:

$emailBody = eregi_replace("[\]",'',$emailBody);

To convert that you’ll need to do this:

$emailBody = preg_replace("/\\\\/", '', $emailBody);

Wondering why there are so MANY escaping backslashes there? I asked that question and got this answer:

“..the backslash needs to be escaped once for the php string’s benefit, then again for the interpretation of the regular expression engine, as escaped characters like \d indicate a digit in regular expressions. So a pattern of \\d would match a digit, but \\\\d would match a backslash then a d character. PHP strings are lenient on backslashing when it isn’t necessary, so:
- setting a string to “\d” will give it a value of \d (the same as setting it to “\\d”).
- but setting it to “\”" will give a value of “.
- and setting it to “\” will return a syntax error.

- PHP double quoted strings will consume the (first) backslash for \\ \n \t \r and \”.
- PHP single quoted strings will only consume the first backslash for \\ and \’ “

There.. clear as mud!

I have a ton of date strings in the stupid US style dd/mm/yy format. i.e. 12/24/09 being 24th September 2009. I need to convert them to the UK style dd/mm/yy.

Solution 1

As a string in PHP is really just an array of characters, the simplest fix was to address the individual number characters by their positions within the sting, and rearrange them into the format I wanted:

$d = "12/24/09";
$d = $d[3].$d[4]."/".$d[0].$d[1]."/".$d[6].$d[7];
echo $d; // displays "24/12/19".

Solution 2

I posted my solution on twitter (@hutchings) and asked for comments and @londonhackspace organiser Jonty came back with the following elegant (and much cleverer) suggestion:

$d = "12/24/09";
$d = preg_replace('|(\d+)/(\d+)/(\d+)|', '$2/$1/$3', $d);
echo $d; // displays "24/12/19".

So provided you know that your original string is in US format, both these solutions can be used. In my testing I found solution 1 executed more quickly, but isn’t as pleasing to look at Cheers Jonty.