用正则表达式读取 XML

<?php
  $xml = "";
  $f = fopen( 'books.xml', 'r' );
  while( $data = fread( $f, 4096 ) ) { $xml .= $data; }
  fclose( $f );
 
  preg_match_all( "/\<book\>(.*?)\<\/book\>/s",
  $xml, $bookblocks );
 
  foreach( $bookblocks[1] as $block )
  {
  preg_match_all( "/\<author\>(.*?)\<\/author\>/",
  $block, $author );
  preg_match_all( "/\<title\>(.*?)\<\/title\>/",
  $block, $title );
  preg_match_all( "/\<publisher\>(.*?)\<\/publisher\>/",
  $block, $publisher );
  echo( $title[1][0]." - ".$author[1][0]." - ".
  $publisher[1][0]."\n" );
  }
  ?>