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。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 $str; }使用方法如下：复制代码 代码如下:message("操作提示","操作成功！","//www.rzxsoft.cn/");13、PHP计算时长
我们在处理时间时，需要计算当前时间距离某个时间点的时长，如计算客户端运行时长，通常用hh:mm:ss表示。复制代码 代码如下:function changeTimeType($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：
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;} 