一些使用频率比较高的php函数_PHP教程

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 $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; $i if(ord($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{
$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=@#@#)
{
$html ="";
if(!empty($url))
$html .="";
$html .="";
$html .="



";
$html .="