常用得php函数：随机字符串，截取字符串，取得客户端ip地址………
在php开发中，我们经常会遇到一些函数，下面是整理好的，可以直接使用，方便开发效率，不过建议大家一定要先看懂，然后在这个基础上增加功能就提高了自身能力了
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 $hash;
}
2.截取一定长度的字符串
注：该函数对gb2312使用有效
function wordscut($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
function createdir($dir=@#@#)
{
if (!is_dir($dir))
{
$temp = explode(@#/@#,$dir);
$cur_dir = @#@#;
for($i=0;$i<count($temp);$i++)
{
$cur_dir .= $temp[$i].@#/@#;
if (!is_dir($cur_dir))
{
@mkdir($cur_dir,0777);
}
}
}
}
5.判断邮箱地址
function checkemail($inaddress)
{
return (ereg("^([a-za-z0-9_-])+@([a-za-z0-9_-])+(\.[a-za-z0-9_-])+",$inaddress));
}
6.跳转
function gotourl($message=@#@#,$url=@#@#,$title=@#@#)
{
$html ="<html><head>";
if(!empty($url))
$html .="<metahttp-equiv=@#refresh@# content=\"3;url=@#".$url."@#\">";
$html .="<linkhref=@#../templates/style.css@# type=text/css rel=stylesheet>";
$html .="</head><body><br><br><br><br>";
$html .="<tablecellspacing=@#0@#cellpadding=@#0@#border=@#1@#width=@#450@#align=@#center@#>";
$html .="<tr><tdbgcolor=@##ffffff@#>";
$html .="<tableborder=@#1@#cellspacing=@#1@#cellpadding=@#4@#width=@#100%@#>";
$html .="<trclass=@#m_title@#>";
$html .="<td>".$title."</td></tr>";
$html .="<trclass=@#line_1@#><tdalign=@#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=@##@#=@#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;
$out="共<font ".$totalpage."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)
$out .= "<ahref=@#?page=1&&".$string."@#title=第一页>第一页</a> ";
if($start>1)
$out.="<ahref=@#?page=".$prestart."@# title=上一页>..<<</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)
$out.="<ahref=@#?page=".$nextend."&&".$string."@# title=下一页>>>..</a>";
if($page<>$totalpage)
$out .= " <ahref=@#?page=".$totalpage."&&".$string."@# title=最后页>最后页</a>";
return $out;
}
8.获取新插入数据的id
<?
mysql_insert_id();
?>