Heim >Backend-Entwicklung >PHP-Tutorial >非常实用的PHP常用函数汇总_php技巧
本文实例总结了一些在php应用开发中常用到的函数,这些函数有字符操作,文件操作及其它的一些操作了,分享给大家供大家参考。具体如下:
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。
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:
以下函数可以快速获取文件的扩展名即后缀。
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。
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:
如果你想列出目录下的所有文件,使用以下代码即可:
以下函数可以获取当前页面的URL,不管是http还是https。
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。
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。
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:
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:
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:
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。
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:
本文汇总了常用的PHP函数,包括获取客户端IP,字符串截取,下载等,详情请查看如下代码:
<?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; }