PHP項目開發中最常用的自定義函數，php開發中，經常需要用到的。其實很多成熟的cms系統中都有的。
 

<?php //alert提示 function alert($msg){ echo "<script>alert('$msg');</script>"; } //把一些預定義的字符轉換為 HTML 實體 function d_htmlspecialchars($string) { if(is_array($string)) { foreach($string as $key => $val) { $string[$key] = d_htmlspecialchars($val); } } else { $string = str_replace('&', '&', $string); $string = str_replace('"', '"', $string); $string = str_replace(''', ''', $string); $string = str_replace('<', '<', $string); $string = str_replace('>', '>', $string); $string = preg_replace('/&(#/d;)/', '&/1', $string); } return $string; } //在預定義字符前加上反斜杠，包括 單引號、雙引號、反斜杠、NULL，以保護數據庫安全 function d_addslashes($string, $force = 0) { if(!$GLOBALS['magic_quotes_gpc'] || $force) { if(is_array($string)) { foreach($string as $key => $val) $string[$key] = d_addslashes($val, $force); } else $string = addslashes($string); } return $string; } //生成隨機字符串，包含大寫、小寫字母、數字 function randstr($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 $hash; } //轉換時間戳為常用的日期格式 function trans_time($timestamp){ if($timestamp < 1) echo '無效的Unix時間戳'; else return date("Y-m-d H:i:s",$timestamp); } //獲取IP function get_ip() { if ($_SERVER["HTTP_X_FORWARDED_FOR"]) $ip = $_SERVER["HTTP_X_FORWARDED_FOR"]; else if ($_SERVER["HTTP_CLIENT_IP"]) $ip = $_SERVER["HTTP_CLIENT_IP"]; else if ($_SERVER["REMOTE_ADDR"]) $ip = $_SERVER["REMOTE_ADDR"]; else if (getenv("HTTP_X_FORWARDED_FOR")) $ip = getenv("HTTP_X_FORWARDED_FOR"); else if (getenv("HTTP_CLIENT_IP")) $ip = getenv("HTTP_CLIENT_IP"); else if (getenv("REMOTE_ADDR")) $ip = getenv("REMOTE_ADDR"); else $ip = "Unknown"; return $ip; } //計算時間差：默認返回類型為“分鐘” //$old_time 只能是時間戳，$return_type 為 h 是小時，為 s 是秒 function timelag($old_time,$return_type='m'){ if($old_time < 1){ echo '無效的Unix時間戳'; }else{ switch($return_type){ case 'h': $type = 3600; break; case 'm': $type = 60; break; case 's': $type = 1; break; case '': $type = 60; break; } $dif = round( (time()-$old_time)/$type ) ; return $dif; } } //獲取當前頁面的URL地址 function url_this(){ $url = "http://".$_SERVER ["HTTP_HOST"].$_SERVER["REQUEST_URI"]; $return_url = "<a href='$url'>$url</a>"; return $return_url; } //跳轉函數 function url_redirect($url,$delay=''){ if($delay == ''){ echo "<script>window.location.href='$url'</script>"; }else{ echo "<meta http-equiv='refresh' content='$delay;URL=$url' />"; } } } //end func ?>