variable_extractor.php

散列函数源代码,散列表通常是关键字和值对应的数据结构,散列函数用于把关键字映射到相应的数组索引号,由于散列表中每个元素访问到的概率不同,所以应该选用不同的散列函数,以提高程序的查找效率.

<?php

// Extract variable names from an PHP script
// (c) Peter Kankowski, 2008

$lines = file('php://stdin');
$vars = array();

foreach($lines as $line) {
   if( preg_match_all('/\$[a-zA-Z_][a-zA-Z_0-9]*/', $line, $matches, PREG_PATTERN_ORDER) ) {
      foreach($matches[0] as $var)
        if(isset($vars[$var]))
          $vars[$var]++;
        else
          $vars[$var] = 1;
   }
}

arsort($vars, SORT_NUMERIC);

foreach($vars as $var => $count) {
   //echo "$var $count\r\n";
   echo "$var\r\n";
}

?>