[PHP]實用函數2

1、產生隨機字串函數

複製代碼 代碼如下: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、截取一定長度的字串（該函數對GB2312使用有效） 複製代碼 代碼如下:function Wordscut($string, $length ,$sss=0) {
if(strlen($string) > $length) {
if($sss){
$length=$length - 3;
$addstr=@# ...@#;
}
for($i = 0; $i < $length; $i++) {
if(ord($string[$i]) > 127) {
$wordscut .= $string[$i].$string[$i + 1];
$i++;
} else {
$wordscut .= $string[$i];
}
}
return $wordscut.$addstr;
}
return $string;
}

3、取得用戶端IP地址 複製代碼 代碼如下: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、判斷郵箱地址 複製代碼 代碼如下:function checkEmail($inAddress)
{
return (ereg("^([a-zA-Z0-9_-])+@([a-zA-Z0-9_-])+(\.[a-zA-Z0-9_-])+",$inAddress));
}

5、分頁（兩個函數配合使用） 複製代碼 代碼如下: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;
$out="共<font ".$totalpage."color=@#red@#><b>".$totalpage."</b></font>頁 ";
$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=第一頁>第一頁</a> ";
if($start>1)
$out.="<a href=@#?page=".$prestart."@# title=上一頁>..<<</a> ";

for($t=$start;$t<=$end;$t++)
{
$out .= ($page==$t) ? "<font [".$t."]color=@#red@#><b>[".$t."]</b></font> " : "<a $thref=@#?page=$t&&".$string."@#>$t</a> ";
}
if($end<$totalpage)
$out.="<a href=@#?page=".$nextend."&&".$string."@# title=下一頁>>>..</a>";
if($page<>$totalpage)
$out .= " <a href=@#?page=".$totalpage."&&".$string."@# title=最後頁>最後頁</a>";
return $out;
}

6、擷取新插入資料的ID 複製代碼 代碼如下:<?
mysql_insert_id();
?>