一些使用频率比较高的php函数

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))

  $html .="<meta http-equiv=@#refresh@# content=\"3;url=@#".$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=@##@# =@#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)

  $out .= "<a href=@#?page=1&&".$string."@#title=第一页>第一页</a> ";

  if($start>1)

  $out.="<a href=@#?page=".$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)

  $out.="<a href=@#?page=".$nextend."&&".$string."@# title=下一页>>>..</a>";

  if($page<>$totalpage)

  $out .= " <a href=@#?page=".$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();

  ?>