一些常用的函数

2024-05-04 22:57:36

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来源：转载

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这是一些使用频率比较高的函数，有的来自别人的程序......

1.产生随机字符串函数

function random($length) {
$hash = '';
$chars = 'abcdefghijklmnopqrstuvwxyz0123456789abcdefghijklmnopqrstuvwxyz';
$max = strlen($chars) - 1;
mt_srand((double)microtime() * 1000000);
for($i = 0; $i < $length; $i++) {
$hash .= $chars[mt_rand(0, $max)];
}
return $hash;
}

2.截取一定长度的字符串

注：该函数对gb2312使用有效

}
return $string;
}

3.取得客户端ip地址

function getip(){
             if (getenv("http_client_ip") && strcasecmp(getenv("http_client_ip"), "unknown"))
                   $ip = getenv("http_client_ip");
             else if (getenv("http_x_forwarded_for") && strcasecmp(getenv("http_x_forwarded_for"), "unknown"))
                   $ip = getenv("http_x_forwarded_for");
             else if (getenv("remote_addr") && strcasecmp(getenv("remote_addr"), "unknown"))
                   $ip = getenv("remote_addr");
             else if (isset($_server['remote_addr']) && $_server['remote_addr'] && strcasecmp($_server['remote_addr'], "unknown"))
                   $ip = $_server['remote_addr'];
             else
                  $ip = "unknown";
             return($ip);
}

4.创建相应的文件夹

5.判断邮箱地址

function checkemail($inaddress)
{
return (ereg("^([a-za-z0-9_-])[email protected]([a-za-z0-9_-])+(/.[a-za-z0-9_-])+",$inaddress));

}

6.跳转

function gotourl($message='',$url='',$title='')
{

    $html ="<html><head>";
    if(!empty($url))
    $html .="<meta http-equiv='refresh' content=/"3;url='".$url."'/">";
    $html .="<link href='../templates/style.css' type=text/css rel=stylesheet>";
    $html .="</head><body><br><br><br><br>";
    $html .="<table cellspacing='0' cellpadding='0' border='1' width='450' align='center'>";
$html .="<tr><td bgcolor='#ffffff'>";
$html .="<table border='1' cellspacing='1' cellpadding='4' width='100%'>";
$html .="<tr class='m_title'>";
$html .="<td>".$title."</td></tr>";
$html .="<tr class='line_1'><td align='center' height='60'>";
$html .="<br>".$message."<br><br>";
    if (!empty($url))
    $html .="系统将在3秒后返回<br>如果您的浏览器不能自动返回,请点击[<a href=".$url." target=_self>这里</a>]进入";
    else
    $html .="[<a href='#' onclick='history.go(-1)'>返回</a>]";
    $html .="</td></tr></table></td></tr></table>";
$html .="</body></html>";
echo $html;
exit;
}

7.分页（两个函数配合使用）

function getpage($sql,$page_size=20)
{
      global $page,$totalpage,$sums; //out param
      $page = $_get["page"];
      //$eachpage = $page_size;
      $pagesql = strstr($sql," from ");
      $pagesql = "select count(*) as ids ".$pagesql;
      $result = mysql_query($pagesql);
      if($rs = mysql_fetch_array($result)) $sums = $rs[0];
      $totalpage = ceil($sums/$page_size);
      if((!$page)||($page<1)) $page=1;
   $startpos = ($page-1)*$page_size;
   $sql .=" limit $startpos,$page_size ";
    return $sql;
}

function showbar($string="")
{
    global $page,$totalpage;
$out="共<font color='red'><b>".$totalpage."</b></font>页  ";
    $linknum =4;
    $start = ($page-round($linknum/2))>0 ? ($page-round($linknum/2)) : "1";
    $end   = ($page+round($linknum/2))<$totalpage ? ($page+round($linknum/2)) : $totalpage;
    $prestart=$start-1;
    $nextend=$end+1;
    if($page<>1)
$out .= "<a href='?page=1&&".$string."'title=第一页>第一页</a> ";
    if($start>1)
$out.="<a href='?page=".$prestart."' title=上一页>..<<</a> ";
for($t=$start;$t<=$end;$t++)
    {
     $out .= ($page==$t) ? "<font color='red'><b>[".$t."]</b></font> " : "<a href='?page=$t&&".$string."'>$t</a> ";
    }
if($end<$totalpage)
$out.="<a href='?page=".$nextend."&&".$string."' title=下一页>>>..</a>";
    if($page<>$totalpage)
   $out .= " <a href='?page=".$totalpage."&&".$string."' title=最后页>最后页</a>";
   return $out;
}

?>