<?php
// 安全覆盖文件写入，防止写入失败文件丢失，如果您的代码中有以"w"模式写入文件的代码
// 推荐改用 f_xwrite() 的方式写入.
// $Id: f_xwrite.php,v 1.2 2004/12/03 05:27:04 hightman Exp $

function f_xwrite($fpath, $buf, $length = -1) {
    $ret = 0;
   
    if ($length < 0) $length = strlen($buf);
    if ($length == 0) {
        @unlink($fpath);
         return 1;
    }
   
    $fd = @fopen($fpath, "r+");
    if (!$fd) $fd = @fopen($fpath, "w");
    if (!$fd) return $ret;

    flock($fd, LOCK_EX);
    fseek($fd, 0, SEEK_SET);
    if (fwrite($fd, $buf, $length)) {
        ftruncate($fd, $length);
        $ret = 1;
    }
    flock($fd, LOCK_UN);
    fclose($fd);
    return $ret;
}
?>