Some commonly used php functions_PHP tutorial-PHP Tutorial-php.cn

1. Generate random string function

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. Intercept a string of a certain length

Note: This function is valid for GB2312

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. Get the client IP address

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");                               _SERVER['REMOTE_ADDR ']) && $_SERVER['REMOTE_ADDR'] && strcasecmp($_SERVER['REMOTE_ADDR'], "unknown"))
$ip = $_SERVER['REMOTE_ADDR'];
else
$ip = "unknown";
return($ip);
}
?>

4. Create the corresponding folder

function createdir($dir='')
{
if (!is_dir($dir))
{
$temp = explode('/',$dir);
$cur_dir = '';
           for($i= 0;$i                                                                                                                             🎜 >                                                                            🎜>}
?>

5. Determine the email address

function checkEmail($inAddress)
{
return (ereg("^([a-zA-Z0-9_-]) +@([a-zA-Z0-9_-])+(.[a-zA-Z0-9_-])+",$inAddress));
}
?>

6. Jump

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

$html ="";
if(!empty($url))
$html .="";
$html .="";
$html .="

";
$html .="

";
$html .="";
$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;
$out="共".$totalpage."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)
$out .= "第一页 ";
    if($start>1)
$out.="..<< ";
for($t=$start;$t<=$end;$t++)
    {
     $out .= ($page==$t) ? "[".$t."] " : "$t ";
    }
if($end<$totalpage)
$out.=">>..";
    if($page<>$totalpage)
   $out .= " 最后页";
   return $out;
}

?>

Related labels：

length php function string use random

source：php.cn

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