PHP 是目前使用最广泛的基于 Web 的编程语言，驱动着数以百万计的网站，其中也包括如 Facebook 等一些大型站点。这里收集了 21个日常开发中实用便捷的 PHP 代码，希望可以对一些 PHP 开发者都会有所帮助。
1. 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。
<?php
/**
* @param 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;
}
?>
2. 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。
<?php
/**
*@param $l - length of random string
*/
function generate_rand($l) {
$c= "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789";
srand((double)microtime()*1000000);
for ($i=0; $i<$l; $i++) {
$rand.= $c[rand()%strlen($c)];
}
return $rand;
}
?>
3. 编码电子邮件地址
使用此代码，可以将任何电子邮件地址编码为 HTML 字符实体，以防止被垃圾邮件程序收集。
<?php
function encode_email($email = \'info@domain.com\', $linkText = \'Contact Us\', $attrs = \'class="emailencoder"\') {
// remplazar aroba y puntos
$email = str_replace(\'@\', \'@\', $email);
$email = str_replace(\'.\', \'.\', $email);
$email = str_split($email, 5);
$linkText = str_replace(\'@\', \'@\', $linkText);
$linkText = str_replace(\'.\', \'.\', $linkText);
$linkText = str_split($linkText, 5);
$part1 = \'<a href="ma\';
$part2 = \'ilto:\';
$part3 = \'" \'. $attrs .\' >\';
$part4 = \'</a>\';
$encoded = \'<script type="text/javascript">\';
$encoded .= "document.write(\'$part1\');";
$encoded .= "document.write(\'$part2\');";
foreach ($email as $e) {
$encoded .= "document.write(\'$e\');";
}
$encoded .= "document.write(\'$part3\');";
foreach ($linkText as $l) {
$encoded .= "document.write(\'$l\');";
}
$encoded .= "document.write(\'$part4\');";
$encoded .= \'</script>\';
return $encoded;
}
?>
4. 验证邮件地址
电子邮件验证也许是中最常用的网页表单验证，此代码除了验证电子邮件地址，也可以选择检查邮件域所属 DNS 中的 MX 记录，使邮件验证功能更加强大。
<?php
function is_valid_email($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, $mxrecords);
} else {
return TRUE;
}
} else {
return FALSE;
}
}
?>
5. 列出目录内容
<?php
function list_files($dir) {
if (is_dir($dir)) {
if ($handle = opendir($dir)) {
while (($file = readdir($handle)) !== FALSE) {
if ($file != "." && $file != ".." && $file != "Thumbs.db") {
echo \'<a target="_blank" href="\' . $dir . $file . \'">\' . $file . \'</a><br />\' . "
";
}
}
closedir($handle);
}
}
}
?>
6. 删除目录
删除一个目录，包括它的内容。
<?php
/**
*@param $dir - Directory to destroy
*@param $virtual[optional]- whether a virtual directory
*/
function destroyDir($dir, $virtual = FALSE) {
$ds = DIRECTORY_SEPARATOR;
$dir = $virtual ? realpath($dir) : $dir;
$dir = substr($dir, -1) == $ds ? substr($dir, 0, -1) : $dir; // 去掉尾部的文件夹分隔符
if (is_dir($dir) && $handle = opendir($dir)) {
while ($file = readdir($handle)) {
if ($file == \'.\' || $file == \'..\') {
continue;
} else if (is_dir($dir . $ds . $file)) {
destroyDir($dir . $ds . $file);
} else {
unlink($dir . $ds . $file);
}
}
closedir($handle);
rmdir($dir);
return TRUE;
} else {
return FALSE;
}
}
?>
7. 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。
<?php
$json_string = \'{"id":1,"name":"foo","email":"foo@foobar.com","interest":["wordpress","php"]} \';
$obj = json_decode($json_string);
echo $obj->name; //prints foo
echo $obj->interest[1]; //prints php
?>
8. 解析 XML 数据
<?php
//xml string
$xml_string="<?xml version=\'1.0\'?>
<users>
<user id=\'398\'>
<name>Foo</name>
<email>foo@bar.com</name>
</user>
<user id=\'867\'>
<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[\'id\'], \' \';
//subnodes are accessed by -> operator
echo $user->name, \' \';
echo $user->email, \'<br />\';
}
?>
9. 创建日志缩略名
创建用户友好的日志缩略名。
<?php
function create_slug($string) {
$slug = preg_replace(\'/[^A-Za-z0-9-]+/\', \'-\', $string);
return $slug;
}
?>
10. 获取客户端真实 IP 地址
该函数将获取用户的真实 IP 地址，即便他使用代理服务器。
<?php
function getRealIpAddr() {
if (!emptyempty($_SERVER[\'HTTP_CLIENT_IP\'])) {
$ip=$_SERVER[\'HTTP_CLIENT_IP\'];
} elseif (!emptyempty($_SERVER[\'HTTP_X_FORWARDED_FOR\'])) { //to check ip is pass from proxy
$ip=$_SERVER[\'HTTP_X_FORWARDED_FOR\'];
} else {
$ip=$_SERVER[\'REMOTE_ADDR\'];
}
return $ip;
}
?>
11. 强制性文件下载
为用户提供强制性的文件下载功能。
<?php
/**
*@param $file - path to file
*/
function force_download($file) {
if ((isset($file)) && (file_exists($file))) {
header("Content-length: " . filesize($file));
header(\'Content-Type: application/octet-stream\');
header(\'Content-Disposition: attachment; filename="\' . $file . \'"\');
readfile("$file");
} else {
echo "No file selected";
}
}
?>
12. 创建标签云
<?php
function getCloud( $data = array(), $minFontSize = 12, $maxFontSize = 30 ) {
$minimumCount = min( array_values( $data ) );
$maximumCount = max( array_values( $data ) );
$spread = $maximumCount - $minimumCount;
$cloudHTML = \'\';
$cloudTags = array();
$spread == 0 && $spread = 1; // 假如等于0，则强制为1
foreach ($data as $tag => $count) {
$size = $minFontSize + ( $count - $minimumCount ) * ( $maxFontSize - $minFontSize ) / $spread;
$cloudTags[] = \'<a style="font-size: \' . floor( $size ) . \'px\'
. \'" href="#" title="\'\' . $tag .
\'\' returned a count of \' . $count . \'">\'
. htmlspecialchars( stripslashes( $tag ) ) . \'</a>\';
}
return join( "
", $cloudTags ) . "
";
}
/**************************
*** Sample usage
*************************/
$arr = array(\'Actionscript\' => 35, \'Adobe\' => 22, \'Array\' => 44, \'Background\' => 43,
\'Blur\' => 18, \'Canvas\' => 33, \'Class\' => 15, \'Color Palette\' => 11, \'Crop\' => 42,
\'Delimiter\' => 13, \'Depth\' => 34, \'Design\' => 8, \'Encode\' => 12, \'Encryption\' => 30,
\'Extract\' => 28, \'Filters\' => 42);
echo getCloud($arr, 12, 36);
?>
13. 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。
<?php similar_text($string1, $string2, $percent); //$percent will have the percentage of similarity ?>
14. 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。
<?php
/**
* @param $email - Email address to show gravatar for
* @param $size - size of gravatar
* @param $default - URL of default gravatar to use
* @param $rating - rating of Gravatar(G, PG, R, X)
*/
function show_gravatar($email, $size, $default, $rating) {
echo \'<img src="http://www.gravatar.com/avatar.php?gravatar_id=\' . md5($email) .
\'&default=\' . $default . \'&size=\' . $size . \'&rating=\' . $rating . \'" width="\' . $size . \'px"
height="\' . $size . \'px" />\';
}
?>
15. 在字符断点处截断文字
所谓断字 (word break)，即一个单词可在转行时断开的地方。这一函数将在断字处截断字符串。
<?php
// Original PHP code by Chirp Internet: www.chirp.com.au
// Please acknowledge use of this code by including this header.
function myTruncate($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, \' \');
?>
16. 文件 Zip 压缩
<?php
/* creates a compressed zip file */
function create_zip($files = array(),$destination = \'\',$overwrite = false) {
//if the zip file already exists and overwrite is false, return false
if (file_exists($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,$file);
}
//debug
//echo \'The zip archive contains \',$zip->numFiles,\' files with a status of \',$zip->status;
//close the zip -- done!
$zip->close();
//check to make sure the file exists
return file_exists($destination);
} else {
return false;
}
}
/***** Example Usage ***/
$files = array(\'file1.jpg\', \'file2.jpg\', \'file3.gif\');
create_zip($files, \'myzipfile.zip\', true);
?>
17. 解压缩 Zip 文件
<?php
/**
* @param $file - path to zip file
* @parm $destination - destination directory for unzipped files
*/
function unzip_file($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 \'Archive extracted to directory\';
}
?>
18. 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。
<?php
if (!preg_match("/^(http|ftp):/", $_POST[\'url\'])) {
$_POST[\'url\'] = \'http://\' . $_POST[\'url\'];
}
?>
19. 将网址字符串转换成超级链接
该函数将 URL 和 E-mail 地址字符串转换为可点击的超级链接。
<?php
function makeClickableLinks($text) {
$text = eregi_replace(\'(((f|ht){1}tp://)[-a-zA-Z0-9@:%_+.~#?&//=]+)\', \'<a href="1">1</a>\', $text);
$text = eregi_replace(\'([[:space:]()[{}])(www.[-a-zA-Z0-9@:%_+.~#?&//=]+)\', \'1<a href="http://2">2</a>\', $text);
$text = eregi_replace(\'([_.0-9a-z-]+@([0-9a-z][0-9a-z-]+.)+[a-z]{2,3})\', \'<a href="mailto:1">1</a>\', $text);
return $text;
}
?>
20. 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。
<?php
/**
* @param $filename - path to the image
* @param $tmpname - temporary path to thumbnail
* @parm $xmax - max width
* @param $ymax - max height
*/
function resize_image($filename, $tmpname, $xmax, $ymax) {
$ext = explode(".", $filename);
$ext = $ext[count($ext)-1];
if ($ext == "jpg" || $ext == "jpeg") {
$im = imagecreatefromjpeg($tmpname);
} else if ($ext == "png") {
$im = imagecreatefrompng($tmpname);
} else if ($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 $im2;
}
?>
21. 检测 Ajax 请求
大多数的 JavaScript 框架如 jQuery，Mootools 等，在发出 Ajax 请求时，都会发送额外的 HTTP_X_REQUESTED_WITH 头部信息，头当他们一个ajax请求，因此你可以在服务器端侦测到 Ajax 请求。
<?php
if (!empty($_SERVER[\'HTTP_X_REQUESTED_WITH\']) && strtolower($_SERVER[\'HTTP_X_REQUESTED_WITH\']) == \'xmlhttprequest\'){
//If AJAX Request Then
} else {
//something else
}
?>