非常实用的PHP常用函数汇总

来源:互联网 发布:js数组常用方法 编辑:程序博客网 时间:2024/05/01 03:54
http://www.jb51.net/article/58610.htm
1、PHP加密解密PHP加密和解密函数可以用来加密一些有用的字符串存放在数据库里,并且通过可逆解密字符串,该函数使用了base64和MD5加密和解密。复制代码 代码如下:function encryptDecrypt($key, $string, $decrypt){     if($decrypt){         $decrypted = rtrim(mcrypt_decrypt(MCRYPT_RIJNDAEL_256, md5($key), base64_decode($string), MCRYPT_MODE_CBC, md5(md5($key))), "12");         return $decrypted;     }else{         $encrypted = base64_encode(mcrypt_encrypt(MCRYPT_RIJNDAEL_256, md5($key), $string, MCRYPT_MODE_CBC, md5(md5($key))));         return $encrypted;     } }使用方法如下:复制代码 代码如下://以下是将字符串“Helloweba欢迎您”分别加密和解密 //加密: echo encryptDecrypt('password', 'Helloweba欢迎您',0); //解密: echo encryptDecrypt('password', 'z0JAx4qMwcF+db5TNbp/xwdUM84snRsXvvpXuaCa4Bk=',1);2、PHP生成随机字符串当我们需要生成一个随机名字,临时密码等字符串时可以用到下面的函数:复制代码 代码如下:function generateRandomString($length = 10) {     $characters = '0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ';     $randomString = '';     for ($i = 0; $i < $length; $i++) {         $randomString .= $characters[rand(0, strlen($characters) - 1)];     }     return $randomString; }使用方法如下:复制代码 代码如下:echo generateRandomString(20);3、PHP获取文件扩展名(后缀)以下函数可以快速获取文件的扩展名即后缀。复制代码 代码如下:function getExtension($filename){   $myext = substr($filename, strrpos($filename, '.'));   return str_replace('.','',$myext); }使用方法如下:复制代码 代码如下:$filename = '我的文档.doc'; echo getExtension($filename);4、PHP获取文件大小并格式化以下使用的函数可以获取文件的大小,并且转换成便于阅读的KB,MB等格式。复制代码 代码如下:function formatSize($size) {     $sizes = array(" Bytes", " KB", " MB", " GB", " TB", " PB", " EB", " ZB", " YB");     if ($size == 0) {          return('n/a');      } else {       return (round($size/pow(1024, ($i = floor(log($size, 1024)))), 2) . $sizes[$i]);      } }使用方法如下:复制代码 代码如下:$thefile = filesize('test_file.mp3'); echo formatSize($thefile);5、PHP替换标签字符有时我们需要将字符串、模板标签替换成指定的内容,可以用到下面的函数:复制代码 代码如下:function stringParser($string,$replacer){     $result = str_replace(array_keys($replacer), array_values($replacer),$string);     return $result; }使用方法如下:复制代码 代码如下:$string = 'The {b}anchor text{/b} is the {b}actual word{/b} or words used {br}to describe the link {br}itself'; $replace_array = array('{b}' => '<b>','{/b}' => '</b>','{br}' => '<br />');  echo stringParser($string,$replace_array);6、PHP列出目录下的文件名如果你想列出目录下的所有文件,使用以下代码即可:复制代码 代码如下:function listDirFiles($DirPath){     if($dir = opendir($DirPath)){          while(($file = readdir($dir))!== false){                 if(!is_dir($DirPath.$file))                 {                     echo "filename: $file<br />";                 }          }     } }使用方法如下:复制代码 代码如下:listDirFiles('home/some_folder/');7、PHP获取当前页面URL以下函数可以获取当前页面的URL,不管是http还是https。复制代码 代码如下:function curPageURL() {     $pageURL = 'http';     if (!empty($_SERVER['HTTPS'])) {$pageURL .= "s";}     $pageURL .= "://";     if ($_SERVER["SERVER_PORT"] != "80") {         $pageURL .= $_SERVER["SERVER_NAME"].":".$_SERVER["SERVER_PORT"].$_SERVER["REQUEST_URI"];     } else {         $pageURL .= $_SERVER["SERVER_NAME"].$_SERVER["REQUEST_URI"];     }     return $pageURL; }使用方法如下:复制代码 代码如下:echo curPageURL();8、PHP强制下载文件有时我们不想让浏览器直接打开文件,如PDF文件,而是要直接下载文件,那么以下函数可以强制下载文件,函数中使用了application/octet-stream头类型。复制代码 代码如下:function download($filename){     if ((isset($filename))&&(file_exists($filename))){        header("Content-length: ".filesize($filename));        header('Content-Type: application/octet-stream');        header('Content-Disposition: attachment; filename="' . $filename . '"');        readfile("$filename");     } else {        echo "Looks like file does not exist!";     } }使用方法如下:复制代码 代码如下:download('/down/test_45f73e852.zip');9、PHP截取字符串长度我们经常会遇到需要截取字符串(含中文汉字)长度的情况,比如标题显示不能超过多少字符,超出的长度用...表示,以下函数可以满足你的需求。复制代码 代码如下:/*  Utf-8、gb2312都支持的汉字截取函数  cut_str(字符串, 截取长度, 开始长度, 编码);  编码默认为 utf-8  开始长度默认为 0 */ function cutStr($string, $sublen, $start = 0, $code = 'UTF-8'){     if($code == 'UTF-8'){         $pa = "/[x01-x7f]|[xc2-xdf][x80-xbf]|xe0[xa0-xbf][x80-xbf]|[xe1-xef][x80-xbf][x80-xbf]|xf0[x90-xbf][x80-xbf][x80-xbf]|[xf1-xf7][x80-xbf][x80-xbf][x80-xbf]/";         preg_match_all($pa, $string, $t_string);          if(count($t_string[0]) - $start > $sublen) return join('', array_slice($t_string[0], $start, $sublen))."...";         return join('', array_slice($t_string[0], $start, $sublen));     }else{         $start = $start*2;         $sublen = $sublen*2;         $strlen = strlen($string);         $tmpstr = '';          for($i=0; $i<$strlen; $i++){             if($i>=$start && $i<($start+$sublen)){                 if(ord(substr($string, $i, 1))>129){                     $tmpstr.= substr($string, $i, 2);                 }else{                     $tmpstr.= substr($string, $i, 1);                 }             }             if(ord(substr($string, $i, 1))>129) $i++;         }         if(strlen($tmpstr)<$strlen ) $tmpstr.= "...";         return $tmpstr;     } }使用方法如下:复制代码 代码如下:$str = "jQuery插件实现的加载图片和页面效果"; echo cutStr($str,16);10、PHP获取客户端真实IP我们经常要用数据库记录用户的IP,以下代码可以获取客户端真实的IP:复制代码 代码如下://获取用户真实IP 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); }使用方法如下:复制代码 代码如下:echo getIp();11、PHP防止SQL注入我们在查询数据库时,出于安全考虑,需要过滤一些非法字符防止SQL恶意注入,请看一下函数:复制代码 代码如下:function injCheck($sql_str) {      $check = preg_match('/select|insert|update|delete|'|/*|*|../|./|union|into|load_file|outfile/', $sql_str);    if ($check) {         echo '非法字符!!';         exit;     } else {         return $sql_str;     } }使用方法如下:复制代码 代码如下:echo injCheck('1 or 1=1');12、PHP页面提示与跳转我们在进行表单操作时,有时为了友好需要提示用户操作结果,并跳转到相关页面,请看以下函数:复制代码 代码如下:function message($msgTitle,$message,$jumpUrl){     $str = '<!DOCTYPE HTML>';     $str .= '<html>';     $str .= '<head>';     $str .= '<meta charset="utf-8">';     $str .= '<title>页面提示</title>';     $str .= '<style type="text/css">';     $str .= '*{margin:0; padding:0}a{color:#369; text-decoration:none;}a:hover{text-decoration:underline}body{height:100%; font:12px/18px Tahoma, Arial,  sans-serif; color:#424242; background:#fff}.message{width:450px; height:120px; margin:16% auto; border:1px solid #99b1c4; background:#ecf7fb}.message h3{height:28px; line-height:28px; background:#2c91c6; text-align:center; color:#fff; font-size:14px}.msg_txt{padding:10px; margin-top:8px}.msg_txt h4{line-height:26px; font-size:14px}.msg_txt h4.red{color:#f30}.msg_txt p{line-height:22px}';     $str .= '</style>';     $str .= '</head>';     $str .= '<body>';     $str .= '<div class="message">';     $str .= '<h3>'.$msgTitle.'</h3>';     $str .= '<div class="msg_txt">';     $str .= '<h4 class="red">'.$message.'</h4>';     $str .= '<p>系统将在 <span style="color:blue;font-weight:bold">3</span> 秒后自动跳转,如果不想等待,直接点击 <a href="{$jumpUrl}">这里</a> 跳转</p>';     $str .= "<script>setTimeout('location.replace('".$jumpUrl."')',2000)</script>";     $str .= '</div>';     $str .= '</div>';     $str .= '</body>';     $str .= '</html>';     echo $str; }使用方法如下:复制代码 代码如下:message('操作提示','操作成功!','http://www.jb51.net/');13、PHP计算时长我们在处理时间时,需要计算当前时间距离某个时间点的时长,如计算客户端运行时长,通常用hh:mm:ss表示。复制代码 代码如下:function changeTimeType($seconds) {     if ($seconds > 3600) {         $hours = intval($seconds / 3600);         $minutes = $seconds % 3600;         $time = $hours . ":" . gmstrftime('%M:%S', $minutes);     } else {         $time = gmstrftime('%H:%M:%S', $seconds);     }     return $time; }使用方法如下:复制代码 代码如下:$seconds = 3712; echo changeTimeType($seconds);希望本文所述对大家的PHP程序设计有所帮助。下面特为大家加点料希望大家能喜欢:
<pre name="code" class="php"><?php/** * 获取客户端IP * @return [string] [description] */function getClientIp() { $ip = NULL; if (isset($_SERVER['HTTP_X_FORWARDED_FOR'])) {  $arr = explode(',', $_SERVER['HTTP_X_FORWARDED_FOR']);  $pos = array_search('unknown',$arr);  if(false !== $pos) unset($arr[$pos]);  $ip = trim($arr[0]); }elseif (isset($_SERVER['HTTP_CLIENT_IP'])) {  $ip = $_SERVER['HTTP_CLIENT_IP']; }elseif (isset($_SERVER['REMOTE_ADDR'])) {  $ip = $_SERVER['REMOTE_ADDR']; } // IP地址合法验证 $ip = (false !== ip2long($ip)) ? $ip : '0.0.0.0'; return $ip;} /** * 获取在线IP * @return String */function getOnlineIp($format=0) { global $S_GLOBAL; if(empty($S_GLOBAL['onlineip'])) {  if(getenv('HTTP_CLIENT_IP') && strcasecmp(getenv('HTTP_CLIENT_IP'), 'unknown')) {   $onlineip = getenv('HTTP_CLIENT_IP');  } elseif(getenv('HTTP_X_FORWARDED_FOR') && strcasecmp(getenv('HTTP_X_FORWARDED_FOR'), 'unknown')) {   $onlineip = getenv('HTTP_X_FORWARDED_FOR');  } elseif(getenv('REMOTE_ADDR') && strcasecmp(getenv('REMOTE_ADDR'), 'unknown')) {   $onlineip = getenv('REMOTE_ADDR');  } elseif(isset($_SERVER['REMOTE_ADDR']) && $_SERVER['REMOTE_ADDR'] && strcasecmp($_SERVER['REMOTE_ADDR'], 'unknown')) {   $onlineip = $_SERVER['REMOTE_ADDR'];  }  preg_match("/[\d\.]{7,15}/", $onlineip, $onlineipmatches);  $S_GLOBAL['onlineip'] = $onlineipmatches[0] ? $onlineipmatches[0] : 'unknown'; }  if($format) {  $ips = explode('.', $S_GLOBAL['onlineip']);  for($i=0;$i<3;$i++) {   $ips[$i] = intval($ips[$i]);  }  return sprintf('%03d%03d%03d', $ips[0], $ips[1], $ips[2]); } else {  return $S_GLOBAL['onlineip']; }}   /** * 获取url * @return [type] [description] */function getUrl(){ $pageURL = 'http'; if (isset($_SERVER["HTTPS"]) && $_SERVER["HTTPS"] == "on") { $pageURL .= "s"; } $pageURL .= "://"; if ($_SERVER["SERVER_PORT"] != "80") { $pageURL .= $_SERVER["HTTP_HOST"] . ":" . $_SERVER["SERVER_PORT"] . $_SERVER["REQUEST_URI"]; } else { $pageURL .= $_SERVER["HTTP_HOST"] . $_SERVER["REQUEST_URI"]; } return $pageURL;} /** * 获取当前站点的访问路径根目录 * @return [type] [description] */function getSiteUrl() { $uri = $_SERVER['REQUEST_URI']?$_SERVER['REQUEST_URI']:($_SERVER['PHP_SELF']?$_SERVER['PHP_SELF']:$_SERVER['SCRIPT_NAME']); return 'http://'.$_SERVER['HTTP_HOST'].substr($uri, 0, strrpos($uri, '/')+1);}   /** * 字符串截取,支持中文和其他编码 * @param [string] $str  [字符串] * @param integer $start [起始位置] * @param integer $length [截取长度] * @param string $charset [字符串编码] * @param boolean $suffix [是否有省略号] * @return [type]   [description] */function msubstr($str, $start=0, $length=15, $charset="utf-8", $suffix=true) { if(function_exists("mb_substr")) {  return mb_substr($str, $start, $length, $charset); } elseif(function_exists('iconv_substr')) {  return iconv_substr($str,$start,$length,$charset); } $re['utf-8'] = "/[\x01-\x7f]|[\xc2-\xdf][\x80-\xbf]|[\xe0-\xef][\x80-\xbf]{2}|[\xf0-\xff][\x80-\xbf]{3}/"; $re['gb2312'] = "/[\x01-\x7f]|[\xb0-\xf7][\xa0-\xfe]/"; $re['gbk'] = "/[\x01-\x7f]|[\x81-\xfe][\x40-\xfe]/"; $re['big5'] = "/[\x01-\x7f]|[\x81-\xfe]([\x40-\x7e]|\xa1-\xfe])/"; preg_match_all($re[$charset], $str, $match); $slice = join("",array_slice($match[0], $start, $length)); if($suffix) {  return $slice."…"; } return $slice;} /** * php 实现js escape 函数 * @param [type] $string [description] * @param string $encoding [description] * @return [type]   [description] */function escape($string, $encoding = 'UTF-8'){ $return = null; for ($x = 0; $x < mb_strlen($string, $encoding);$x ++) { $str = mb_substr($string, $x, 1, $encoding); if (strlen($str) > 1) { // 多字节字符  $return .= "%u" . strtoupper(bin2hex(mb_convert_encoding($str, 'UCS-2', $encoding))); } else {  $return .= "%" . strtoupper(bin2hex($str)); } } return $return;}/** * php 实现 js unescape函数 * @param [type] $str [description] * @return [type]  [description] */function unescape($str) { $str = rawurldecode($str); preg_match_all("/(?:%u.{4})|.{4};|&#\d+;|.+/U",$str,$r); $ar = $r[0]; foreach($ar as $k=>$v) {  if(substr($v,0,2) == "%u"){   $ar[$k] = iconv("UCS-2","utf-8//IGNORE",pack("H4",substr($v,-4)));  } elseif(substr($v,0,3) == "") {   $ar[$k] = iconv("UCS-2","utf-8",pack("H4",substr($v,3,-1)));  } elseif(substr($v,0,2) == "&#") {   echo substr($v,2,-1)."";   $ar[$k] = iconv("UCS-2","utf-8",pack("n",substr($v,2,-1)));  } } return join("",$ar);} /** * 数字转人名币 * @param [type] $num [description] * @return [type]  [description] */function num2rmb ($num) { $c1 = "零壹贰叁肆伍陆柒捌玖"; $c2 = "分角元拾佰仟万拾佰仟亿"; $num = round($num, 2); $num = $num * 100; if (strlen($num) > 10) {  return "oh,sorry,the number is too long!"; } $i = 0; $c = ""; while (1) {  if ($i == 0) {   $n = substr($num, strlen($num)-1, 1);  } else {   $n = $num % 10;  }  $p1 = substr($c1, 3 * $n, 3);  $p2 = substr($c2, 3 * $i, 3);  if ($n != '0' || ($n == '0' && ($p2 == '亿' || $p2 == '万' || $p2 == '元'))) {   $c = $p1 . $p2 . $c;  } else {   $c = $p1 . $c;  }  $i = $i + 1;  $num = $num / 10;  $num = (int)$num;  if ($num == 0) {   break;  } } $j = 0; $slen = strlen($c); while ($j < $slen) {  $m = substr($c, $j, 6);  if ($m == '零元' || $m == '零万' || $m == '零亿' || $m == '零零') {   $left = substr($c, 0, $j);   $right = substr($c, $j + 3);   $c = $left . $right;   $j = $j-3;   $slen = $slen-3;  }  $j = $j + 3; } if (substr($c, strlen($c)-3, 3) == '零') {  $c = substr($c, 0, strlen($c)-3); } // if there is a '0' on the end , chop it out return $c . "整";} /** * 特殊的字符 * @param [type] $str [description] * @return [type]  [description] */function makeSemiangle($str) { $arr = array(  '0' => '0', '1' => '1', '2' => '2', '3' => '3', '4' => '4',  '5' => '5', '6' => '6', '7' => '7', '8' => '8', '9' => '9',  'A' => 'A', 'B' => 'B', 'C' => 'C', 'D' => 'D', 'E' => 'E',  'F' => 'F', 'G' => 'G', 'H' => 'H', 'I' => 'I', 'J' => 'J',  'K' => 'K', 'L' => 'L', 'M' => 'M', 'N' => 'N', 'O' => 'O',  'P' => 'P', 'Q' => 'Q', 'R' => 'R', 'S' => 'S', 'T' => 'T',  'U' => 'U', 'V' => 'V', 'W' => 'W', 'X' => 'X', 'Y' => 'Y',  'Z' => 'Z', 'a' => 'a', 'b' => 'b', 'c' => 'c', 'd' => 'd',  'e' => 'e', 'f' => 'f', 'g' => 'g', 'h' => 'h', 'i' => 'i',  'j' => 'j', 'k' => 'k', 'l' => 'l', 'm' => 'm', 'n' => 'n',  'o' => 'o', 'p' => 'p', 'q' => 'q', 'r' => 'r', 's' => 's',  't' => 't', 'u' => 'u', 'v' => 'v', 'w' => 'w', 'x' => 'x',  'y' => 'y', 'z' => 'z',  '(' => '(', ')' => ')', '〔' => '[', '〕' => ']', '【' => '[',  '】' => ']', '〖' => '[', '〗' => ']', '{' => '{', '}' => '}', '《' => '<',  '》' => '>',  '%' => '%', '+' => '+', '—' => '-', '-' => '-', '~' => '-',  ':' => ':', '。' => '.', '、' => ',', ',' => '.', '、' => '.',  ';' => ';', '?' => '?', '!' => '!', '…' => '-', '‖' => '|',  '”' => '"', '“' => '"', ''' => '`', '‘' => '`', '|' => '|', '〃' => '"',  ' ' => ' ','.' => '.'); return strtr($str, $arr);} /** * 下载 * @param [type] $filename [description] * @param string $dir  [description] * @return [type]   [description] */function downloads($filename,$dir='./'){ $filepath = $dir.$filename; if (!file_exists($filepath)){  header("Content-type: text/html; charset=utf-8");  echo "File not found!";  exit; } else {  $file = fopen($filepath,"r");  Header("Content-type: application/octet-stream");  Header("Accept-Ranges: bytes");  Header("Accept-Length: ".filesize($filepath));  Header("Content-Disposition: attachment; filename=".$filename);  echo fread($file, filesize($filepath));  fclose($file); }} /** * 创建一个目录树 * @param [type] $dir [description] * @param integer $mode [description] * @return [type]  [description] */function mkdirs($dir, $mode = 0777) { if (!is_dir($dir)) {  mkdirs(dirname($dir), $mode);  return mkdir($dir, $mode); } return true;}


                                             
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