Summary of 21 common PHP methods-PHP Tutorial-php.cn

Summary of 21 common PHP methods

php常用方法汇总

1. PHP可阅读随机字符串

　　此代码将创建一个可阅读的字符串，使其更接近词典中的单词，实用且具有密码验证功能。

/************** *@length - length of random string (must be a multiple of 2) **************/
 function readable_random_string($length = 6){ $conso=array("b","c","d","f","g","h","j","k","l", "m","n","p","r","s","t","v","w","x","y","z"); $vocal=array("a","e","i","o","u"); $password=""; srand ((double)microtime()*1000000); $max = $length/2; for($i=1; $i<=$max; $i++) { $password.=$conso[rand(0,19)]; $password.=$vocal[rand(0,4)]; } return $password; }

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　　2. PHP生成一个随机字符串

　　如果不需要可阅读的字符串，使用此函数替代，即可创建一个随机字符串，作为用户的随机密码等。

/************* *@l - length of random string */ 
function generate_rand($l){ $c= "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789"; srand((double)microtime()*1000000); for($i=0; $i<$l; $i++) { $rand.= $c[rand()%strlen($c)]; } return $rand; }

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　　3. PHP编码电子邮件地址

　　使用此代码，可以将任何电子邮件地址编码为 html 字符实体，以防止被垃圾邮件程序收集。

function encode_email($email=&#39;info@domain.com&#39;, $linkText=&#39;Contact Us&#39;, $attrs =&#39;class="emailencoder"&#39; ) { // remplazar aroba y puntos $email = str_replace(&#39;@&#39;, &#39;@&#39;, $email); $email = str_replace(&#39;.&#39;, &#39;.&#39;, $email); $email = str_split($email, 5); $linkText = str_replace(&#39;@&#39;, &#39;@&#39;, $linkText); $linkText = str_replace(&#39;.&#39;, &#39;.&#39;, $linkText); $linkText = str_split($linkText, 5); $part1 = &#39;<a href="ma&#39;; $part2 = &#39;ilto:&#39;; $part3 = &#39;" &#39;. $attrs .&#39; >&#39;; $part4 = &#39;</a>&#39;; $encoded = &#39;<script type="text/javascript">&#39;; $encoded .= "document.write(&#39;$part1&#39;);"; $encoded .= "document.write(&#39;$part2&#39;);"; foreach($email as $e) { $encoded .= "document.write(&#39;$e&#39;);"; } $encoded .= "document.write(&#39;$part3&#39;);"; foreach($linkText as $l) { $encoded .= "document.write(&#39;$l&#39;);"; } $encoded .= "document.write(&#39;$part4&#39;);"; $encoded .= &#39;</script>&#39;; return $encoded; }

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　　4. PHP验证邮件地址

　　电子邮件验证也许是中最常用的网页表单验证，此代码除了验证电子邮件地址，也可以选择检查邮件域所属 DNS 中的 MX 记录，使邮件验证功能更加强大。

function is_valid_email($email, $test_mx = false) { if(eregi("^([_a-z0-9-]+)(\.[_a-z0-9-]+)*@([a-z0-9-]+)(\.[a-z0-9-]+)*(\.[a-z]{2,4})$", $email)) if($test_mx) { list($username, $domain) = split("@", $email); return getmxrr($domain, $mxrecords); } else return true; else return false; }

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　　5. PHP列出目录内容

function list_files($dir) { if(is_dir($dir)) { if($handle = opendir($dir)) { while(($file = readdir($handle)) !== false) { if($file != "." && $file != ".." && $file != "Thumbs.db") { echo &#39;<a target="_blank" href="&#39;.$dir.$file.&#39;">&#39;.$file.&#39;</a><br>&#39;."\n"; } } closedir($handle); } } }

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　　6. PHP销毁目录

　　删除一个目录，包括它的内容。

/***** *@dir - Directory to destroy *@virtual[optional]- whether a virtual directory */ 
function destroyDir($dir, $virtual = false) { $ds = DIRECTORY_SEPARATOR; $dir = $virtual ? realpath($dir) : $dir; $dir = substr($dir, -1) == $ds ? substr($dir, 0, -1) : $dir; if (is_dir($dir) && $handle = opendir($dir)) { while ($file = readdir($handle)) { if ($file == &#39;.&#39; || $file == &#39;..&#39;) { continue; } elseif (is_dir($dir.$ds.$file)) { destroyDir($dir.$ds.$file); } else { unlink($dir.$ds.$file); } } closedir($handle); rmdir($dir); return true; } else { return false; } }

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　　7. PHP解析 JSON 数据

　　与大多数流行的 Web 服务如 twitter 通过开放 API 来提供数据一样，它总是能够知道如何解析 API 数据的各种传送格式，包括 JSON，XML 等等。

$json_string=&#39;{"id":1,"name":"foo","email":"foo@foobar.com","interest":["wordpress","php"]} &#39;; $obj=json_decode($json_string); echo $obj->name; //prints foo echo $obj->interest[1]; //prints php

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　　8. PHP解析 XML 数据

//xml string $xml_string="<?xml version=&#39;1.0&#39;?> <users> <user id=&#39;398&#39;> <name>Foo</name> <email>foo@bar.com</name> </user> <user id=&#39;867&#39;> <name>Foobar</name> <email>foobar@foo.com</name> </user> </users>"; //load the xml string using simplexml $xml = simplexml_load_string($xml_string); //loop through the each node of user foreach ($xml->user as $user) { //access attribute echo $user[&#39;id&#39;], &#39; &#39;; //subnodes are accessed by -> operator echo $user->name, &#39; &#39;; echo $user->email, &#39;<br />&#39;; }

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　　9. PHP创建日志缩略名

　　创建用户友好的日志缩略名。

function create_slug($string){ $slug=preg_replace(&#39;/[^A-Za-z0-9-]+/&#39;, &#39;-&#39;, $string); return $slug; }

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　　10. PHP获取客户端真实 IP 地址

　　该函数将获取用户的真实 IP 地址，即便他使用代理服务器。

function getRealIpAddr() { if (!emptyempty($_SERVER[&#39;HTTP_CLIENT_IP&#39;])) { $ip=$_SERVER[&#39;HTTP_CLIENT_IP&#39;]; } elseif (!emptyempty($_SERVER[&#39;HTTP_X_FORWARDED_FOR&#39;])) //to check ip is pass from proxy { $ip=$_SERVER[&#39;HTTP_X_FORWARDED_FOR&#39;]; } else { $ip=$_SERVER[&#39;REMOTE_ADDR&#39;]; } return $ip; }

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　　11. PHP强制性文件下载

　　为用户提供强制性的文件下载功能。

/******************** *@file - path to file */ 
function force_download($file) { if ((isset($file))&&(file_exists($file))) { header("Content-length: ".filesize($file)); header(&#39;Content-Type: application/octet-stream&#39;); header(&#39;Content-Disposition: attachment; filename="&#39; . $file . &#39;"&#39;); readfile("$file"); } else { echo "No file selected"; } }

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　　12. PHP创建标签云

function getCloud( $data = array(), $minFontSize = 12, $maxFontSize = 30 ) { $minimumCount = min( array_values( $data ) ); $maximumCount = max( array_values( $data ) ); $spread = $maximumCount - $minimumCount; $cloudHTML = &#39;&#39;; $cloudTags = array(); $spread == 0 && $spread = 1; foreach( $data as $tag => $count ) { $size = $minFontSize + ( $count - $minimumCount ) * ( $maxFontSize - $minFontSize ) / $spread; $cloudTags[] = &#39;<a style="font-size: &#39; . floor( $size ) . &#39;px&#39; . &#39;" href="#" title="\&#39;&#39; . $tag . &#39;\&#39; returned a count of &#39; . $count . &#39;">&#39; . htmlspecialchars( stripslashes( $tag ) ) . &#39;</a>&#39;; } return join( "\n", $cloudTags ) . "\n"; } /************************** **** Sample usage ***/ $arr = Array(&#39;Actionscript&#39; => 35, &#39;Adobe&#39; => 22, &#39;Array&#39; => 44, &#39;Background&#39; => 43, &#39;Blur&#39; => 18, &#39;Canvas&#39; => 33, &#39;Class&#39; => 15, &#39;Color Palette&#39; => 11, &#39;Crop&#39; => 42, &#39;Delimiter&#39; => 13, &#39;Depth&#39; => 34, &#39;Design&#39; => 8, &#39;Encode&#39; => 12, &#39;Encryption&#39; => 30, &#39;Extract&#39; => 28, &#39;Filters&#39; => 42); echo getCloud($arr, 12, 36);

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　　13. PHP寻找两个字符串的相似性

　　PHP 提供了一个极少使用的 similar_text 函数，但此函数非常有用，用于比较两个字符串并返回相似程度的百分比。

similar_text($string1, $string2, $percent); //$percent will have the percentage of similarity

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　　14. PHP在应用程序中使用 Gravatar 通用头像

　　随着 WordPress 越来越普及，Gravatar 也随之流行。由于 Gravatar 提供了易于使用的 API，将其纳入应用程序也变得十分方便。

/****************** *@email - Email address to show gravatar for *@size - size of gravatar *@default - URL of default gravatar to use *@rating - rating of Gravatar(G, PG, R, X) */ 
 
function show_gravatar($email, $size, $default, $rating) { echo &#39;<img src="http://www.gravatar.com/avatar.php?gravatar_id=&#39;.md5($email). &#39;&default=&#39;.$default.&#39;&size=&#39;.$size.&#39;&rating=&#39;.$rating.&#39;" width="&#39;.$size.&#39;px" height="&#39;.$size.&#39;px" />&#39;; }

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　　15. PHP在字符断点处截断文字

　　所谓断字 (word break)，即一个单词可在转行时断开的地方。这一函数将在断字处截断字符串。

// Original PHP code by Chirp Internet: www.chirp.com.au 
// Please acknowledge use of this code by including this header. function myTruncate($string, $limit, $break=".", $pad="...") { // return with no change if string is shorter than $limit if(strlen($string) <= $limit) return $string; // is $break present between $limit and the end of the string? if(false !== ($breakpoint = strpos($string, $break, $limit))) { if($breakpoint < strlen($string) - 1) { $string = substr($string, 0, $breakpoint) . $pad; } } return $string; } /***** Example ****/ $short_string=myTruncate($long_string, 100, &#39; &#39;);

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　　16. PHP文件 Zip 压缩

/* creates a compressed zip file */ 
function create_zip($files = array(),$destination = &#39;&#39;,$overwrite = false) { 
//if the zip file already exists and overwrite is false, return false if(file_exists($destination) && !$overwrite) { return false; } //vars $valid_files = array(); //if files were passed in... if(is_array($files)) { //cycle through each file foreach($files as $file) { //make sure the file exists if(file_exists($file)) { $valid_files[] = $file; } } } //if we have good files... if(count($valid_files)) { //create the archive $zip = new ZipArchive(); if($zip->open($destination,$overwrite ? ZIPARCHIVE::OVERWRITE : ZIPARCHIVE::CREATE) !== true) { return false; } //add the files foreach($valid_files as $file) { $zip->addFile($file,$file); } //debug //echo &#39;The zip archive contains &#39;,$zip->numFiles,&#39; files with a status of &#39;,$zip->status; //close the zip -- done! $zip->close(); //check to make sure the file exists return file_exists($destination); } else { return false; } } /***** Example Usage ***/ $files=array(&#39;file1.jpg&#39;, &#39;file2.jpg&#39;, &#39;file3.gif&#39;); create_zip($files, &#39;myzipfile.zip&#39;, true);

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　　17. PHP解压缩 Zip 文件

/********************** *@file - path to zip file *@destination - destination directory for unzipped files */ function unzip_file($file, $destination){ // create object $zip = new ZipArchive() ; // open archive if ($zip->open($file) !== TRUE) { die (’Could not open archive’); } // extract contents to destination directory $zip->extractTo($destination); // close archive $zip->close(); echo &#39;Archive extracted to directory&#39;; }

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18. PHP为 URL 地址预设 http 字符串

　　有时需要接受一些表单中的网址输入，但用户很少添加 http:// 字段，此代码将为网址添加该字段。

if (!preg_match("/^(http|ftp):/", $_POST[&#39;url&#39;])) { $_POST[&#39;url&#39;] = &#39;http://&#39;.$_POST[&#39;url&#39;]; }

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　　19. PHP将网址字符串转换成超级链接

　　该函数将 URL 和 E-mail 地址字符串转换为可点击的超级链接。

function makeClickableLinks($text) { $text = eregi_replace(&#39;(((f|ht){1}tp://)[-a-zA-Z0-9@:%_+.~#?&//=]+)&#39;, &#39;<a href="\1">\1</a>&#39;, $text); $text = eregi_replace(&#39;([[:space:]()[{}])(www.[-a-zA-Z0-9@:%_+.~#?&//=]+)&#39;, &#39;\1<a href="http://\2">\2</a>&#39;, $text); $text = eregi_replace(&#39;([_.0-9a-z-]+@([0-9a-z][0-9a-z-]+.)+[a-z]{2,3})&#39;, &#39;<a href="mailto:\1">\1</a>&#39;, $text); return $text; }

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　　20. PHP调整图像尺寸

　　创建图像缩略图需要许多时间，此代码将有助于了解缩略图的逻辑。

/********************** *@filename - path to the image *@tmpname - temporary path to thumbnail *@xmax - max width *@ymax - max height */ 
function resize_image($filename, $tmpname, $xmax, $ymax) { $ext = explode(".", $filename); $ext = $ext[count($ext)-1]; if($ext == "jpg" || $ext == "jpeg") $im = imagecreatefromjpeg($tmpname); elseif($ext == "png") $im = imagecreatefrompng($tmpname); elseif($ext == "gif") $im = imagecreatefromgif($tmpname); $x = imagesx($im); $y = imagesy($im); if($x <= $xmax && $y <= $ymax) return $im; if($x >= $y) { $newx = $xmax; $newy = $newx * $y / $x; } else { $newy = $ymax; $newx = $x / $y * $newy; } $im2 = imagecreatetruecolor($newx, $newy); imagecopyresized($im2, $im, 0, 0, 0, 0, floor($newx), floor($newy), $x, $y); return $im2; }

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　　21. PHP检测 ajax 请求

　　大多数的 JavaScript 框架如 jquery，Mootools 等，在发出 Ajax 请求时，都会发送额外的 HTTP_X_REQUESTED_WITH 头部信息，头当他们一个ajax请求，因此你可以在服务器端侦测到 Ajax 请求。

if(!emptyempty($_SERVER[&#39;HTTP_X_REQUESTED_WITH&#39;]) && strtolower($_SERVER[&#39;HTTP_X_REQUESTED_WITH&#39;]) == &#39;xmlhttprequest&#39;){ //If AJAX Request Then }else{ //something else }

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