fix-serialization.php

#!/usr/bin/php
<?php
/*
* Blogestudio Fix Serialization	1.2
* Fixer script of length attributes for serialized strings (e.g. Wordpress databases)
* License: GPL version 3 or later - http://www.gnu.org/licenses/gpl.txt
* By Pau Iglesias
* http://blogestudio.com
* 
* Inspiration and regular expression code base from David Coveney:
* http://davidcoveney.com/575/php-serialization-fix-for-wordpress-migrations/
* 
* Usage:
*
* 	/usr/bin/php fix-serialization.php my-sql-file.sql
*
* Versions:
* 
* 	1.0 2011-08-03 Initial release
* 	1.1 2011-08-18 Support for backslashed quotes, added some code warnings
* 	1.2 2011-09-29 Support for null or zero length strings after preg_replace is called, and explain how to handle these errors
* 
* Knowed errors:
*
* - Memory size exhausted
* Allowed memory size of 67108864 bytes exhausted (tried to allocate 35266489 bytes)
* How to fix: update php.ini memory_limit to 512M or more, and restart cgi service or web server
*
* - Function preg_replace returns null or 0 length string
* If preg_last_error = PREG_BACKTRACK_LIMIT_ERROR (value 2), increase pcre.backtrack_limit in php.ini (by default 100k, change to 2M by example)
* Same way for others preg_last_error codes: http://www.php.net/manual/en/function.preg-last-error.php
* 
* TODO next versions
* 
* - Check if needed UTF-8 support detecting and adding u PCRE modifier
* 
*/



// Unescape to avoid dump-text issues
function unescape_mysql($value) {
	return str_replace(array("\\\\", "\\0", "\\n", "\\r", "\Z",  "\'", '\"'),
					   array("\\",   "\0",  "\n",  "\r",  "\x1a", "'", '"'), 
					   $value);
}



// Fix strange behaviour if you have escaped quotes in your replacement
function unescape_quotes($value) {
	return str_replace('\"', '"', $value);
}	



// Check command line arguments
if (!(isset($argv) && isset($argv[1]))) {
	
	// Error
	echo 'Error: no input file specified'."\n\n";

// With arguments
} else {
	
	// Compose path from argument
	$path = $argv[1];  // removed dirname allows to use relative paths when script called from other working directory
	if (!file_exists($path)) {
	
		// Error
		echo 'Error: input file does not exists'."\n";
		echo $path."\n\n";
	
	// File exists
	} else {
	
		// Get file contents
		if (!($fp = fopen($path, 'r'))) {
			
			// Error
			echo 'Error: can`t open input file for read'."\n";
			echo $path."\n\n";
		
		// File opened for read
		} else {
			
			// Initializations
			$do_preg_replace = false;
		
			// Copy data
			if (!($data = fread($fp, filesize($path)))) {

				// Error
				echo 'Error: can`t read entire data from input file'."\n";
				echo $path."\n\n";
			
			// Check data
			} elseif (!(isset($data) && strlen($data) > 0)) {

				// Warning
				echo "Warning: the file is empty or can't read contents\n";
				echo $path."\n\n";
			
			// Data ok
			} else {

				// Tag context
				$do_preg_replace = true;

				// Replace serialized string values
				$data = preg_replace_callback('!s:(\d+):([\\\\]?"[\\\\]?"|[\\\\]?"((.*?)[^\\\\])[\\\\]?");!', function($m) {
					if(empty($m[3])) return $m[0]; //dont change anything when no string has 0 chars
    					return 's:'.strlen(unescape_mysql($m[3])).':"'.unescape_quotes($m[3]).'";';
				}, $data);
			}

			// Close file
			fclose($fp);
			
			// Check data
			if (!(isset($data) && strlen($data) > 0)) {
				
				// Check origin
				if ($do_preg_replace) {

					// Error
					echo "Error: preg_replace returns nothing\n";
					if (function_exists('preg_last_error')) echo "preg_last_error() = ".preg_last_error()."\n";
					echo $path."\n\n";
				}
			
			// Data Ok
			} else {

				// And finally write data
				if (!($fp = fopen($path, 'w'))) {

					// Error
					echo "Error: can't open input file for writing\n";
					echo $path."\n\n";
					
				// Open for write
				} else {
					
					// Write file data
					if (!fwrite($fp, $data)) {
						
						// Error
						echo "Error: can't write input file\n";
						echo $path."\n\n";
					}
					
					// Close file
					fclose($fp);
				}
			}
		}
	}
}



?>