Recommended common functions in PHP_PHP tutorial

1. Generate a 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. Obtain 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"))                   $ip = getenv("REMOTE_ADDR"); else if (isset($_SERVER['REMOTE_ADDR']) 

&& $_SERVER['REMOTE_ADDR'] && strcasecmp

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

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4. Create the corresponding folder

function createdir($dir=''){        if (!is_dir($dir))        {            $temp = explode('/',$dir);            $cur_dir = '';            for($i=0;$i<count pre if .="$temp[$i].'/';"></count>

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="'){     $html  ="＜html＞＜head＞";    if(!empty($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. Paging (two functions are used together)

 $totalpage = ceil($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=＞..＜＜＜/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."&&".$string."' title=＞＞＞..＜/a＞";    if($page＜＞$totalpage)   $out .= " ＜a href='?page=".$totalpage."&&".$string."' 

title=最后页＞最后页＜/a＞";   return $out;}?＞

http://www.bkjia.com/PHPjc/446705.htmlwww.bkjia.comtruehttp: //www.bkjia.com/PHPjc/446705.htmlTechArticle1. Generate a random string function function random($length) { $hash = ''; $chars = ' ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789abcdefghijklmnopqrstuvwxyz'; $max = strlen($chars) - 1; mt_srand(...