21个php常用方法汇总
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 $password;
}如果不需要可阅读的字符串，使用此函数替代，即可创建一个随机字符串，作为用户的随机密码等。
/************* *@l - length of random string */
function generate_rand($l)
{
$c = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789";
srand((double)microtime() * 1000000);
for ($i = 0; $i < $l; $i++) {
$rand .= $c[rand() % strlen($c)];
}
return $rand;
}3. PHP编码电子邮件地址
使用此代码，可以将任何电子邮件地址编码为 html 字符实体，以防止被垃圾邮件程序收集。
function encode_email($email = '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 $encoded;
}4. PHP验证邮件地址
电子邮件验证也许是中最常用的网页表单验证，此代码除了验证电子邮件地址，也可以选择检查邮件域所属 DNS 中的 MX 记录，使邮件验证功能更加强大。
function is_valid_email($email, $test_mx = false)
{
if (preg_match("^([_a-z0-9-]+)(\.[_a-z0-9-]+)*@([a-z0-9-]+)(\.[a-z0-9-]+)*(\.[a-z]{2,4})$", $email)) if ($test_mx) {
list($username, $domain) = str_split("@", $email);
return getmxrr($domain, $mxrecords);
} else return true; else return false;
}5. PHP列出目录内容
function list_files($dir)
{
if (is_dir($dir)) {
if ($handle = opendir($dir)) {
while (($file = readdir($handle)) !== false) {
if ($file != "." && $file != ".." && $file != "Thumbs.db") {
echo '<a target="_blank" href="' . $dir . $file . '">' . $file . '</a><br>' . "\n";
}
}
closedir($handle);
}
}
}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 == '.' || $file == '..') {
continue;
} elseif (is_dir($dir . $ds . $file)) {
destroyDir($dir . $ds . $file);
} else {
unlink($dir . $ds . $file);
}
}
closedir($handle);
rmdir($dir);
return true;
} else {
return false;
}
}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 = '{"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 php8. PHP解析 XML 数据
$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 $user->email, '<br/>'; }
9. PHP创建日志缩略名
创建用户友好的日志缩略名。
function create_slug($string)
{
$slug = preg_replace('/[^A-Za-z0-9-]+/', '-', $string);
return $slug;
}10. PHP获取客户端真实 IP 地址
该函数将获取用户的真实 IP 地址，即便他使用代理服务器。
function getRealIpAddr()
{
if (!emptyempty($_SERVER['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 $ip;
}11. PHP强制性文件下载
为用户提供强制性的文件下载功能。
/******************** *@file - path to file */
function force_download($file)
{
if ((isset($file)) && (file_exists($file))) {
header("Content-length: " . filesize($file));
header('Content-Type: application/octet-stream');
header('Content-Disposition: attachment; filename="' . $file . '"');
readfile("$file");
} else {
echo "No file selected";
}
}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 = '';
$cloudTAGs = array();
$spread == 0 && $spread = 1;
foreach ($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("\n", $cloudTags) . "\n";
}
/************************** **** 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. 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
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, $rating)
{
echo '<img src="http://www.gravatar.com/avatar.php?gravatar_id=' . md5($email) . '&default=' . $default . '&size=' . $size .
'&rating=' . $rating . '" width="' . $size . 'px" height="' . $size . 'px" />';
}15. PHP在字符断点处截断文字
所谓断字 (word break)，即一个单词可在转行时断开的地方。这一函数将在断字处截断字符串。
function myTruncate($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. PHP文件 Zip 压缩
/* 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. 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 'Archive extracted to directory';
}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['url'])) {
$_POST['url'] = 'http://' . $_POST['url'];
}19. PHP将网址字符串转换成超级链接
该函数将 URL 和 E-mail 地址字符串转换为可点击的超级链接。
function makeClickableLinks($text)
{
$text = preg_replace('(((f|ht){1}tp://)[-a-zA-Z0-9@:%_+.~#?&//=]+)', '<a href="\1">\1</a>', $text);
$text = preg_replace('([[:space:]()[{}])(www.[-a-zA-Z0-9@:%_+.~#?&//=]+)', '\1<a href="http://\2">\2</a>', $text);
$text = preg_replace('([_.0-9a-z-]+@([0-9a-z][0-9a-z-]+.)+[a-z]{2,3})', '<a href="mailto:\1">\1</a>', $text);
return $text;
}20. PHP调整图像尺寸
创建图像缩略图需要许多时间，此代码将有助于了解缩略图的逻辑。
/********************** *@filename - path to the image *@tmpname - temporary path to thumbnail *@xmax - max width *@ymax - max height */
function resize_image($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 $im2;
}21. PHP检测 ajax 请求
大多数的 Javascript 框架如 jquery，Mootools 等，在发出 Ajax 请求时，都会发送额外的 HTTP_X_REQUESTED_WITH 头部信息，头当他们一个ajax请求，因此你可以在服务器端侦测到 Ajax 请求。
if (!empty($_SERVER['HTTP_X_REQUESTED_WITH']) && strtolower($_SERVER['HTTP_X_REQUESTED_WITH']) == 'xmlhttprequest') {
//If AJAX Request Then
}else{
//something else
}
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