Share with you 21 commonly used PHP function code snippets-PHP Tutorial-php.cn

Share 21 commonly used PHP function code snippets

1. PHP Readable Random String
This code will create a readable string that is closer to the word in the dictionary, practical and has password verification capabilities.
/**************
*@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 $password;
}
2. PHP generates a random string
If you don’t need a readable string, use this function instead , you can create a random string as the user's random password, etc.
/*************
*@l – length of random string
*/
function generate_rand($l){
$c= “ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789″;
srand((double)microtime()*1000000);
for($i=0; < $l; $i++) {
$rand.= $c[rand()%strlen($c)];
}
return $rand;
}
3. PHP encode email address
Use this code, Any email address can be encoded as html character entities to prevent collection by spam programs.
function encode_email($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);
$part1 = '$part2 = 'ilto:';
$part3 = '" '. $attrs .' >';
$part4 = '';
$encoded = '';
return $encoded;
}
4. PHP verification email address
Email verification is perhaps the most commonly used web form verification. In addition to verifying the email address, this code can also choose to check the MX in the DNS to which the email domain belongs. Records to make the email verification function more powerful.
function is_valid_email($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, $mxrecords);
}
else
return true;
else
return false ;
}
5. PHP list directory contents
function list_files($dir)
{
if(is_dir($dir))
{
if($handle = opendir($dir))
{
while( ($file = readdir($handle)) !== false)
{
if($file != “.” && $file != “..” && $file != “Thumbs.db”)
{
echo ''.$file.'
'.”n”;
}
}
closedir($handle);
}
}
}
6. PHP Destroy Directory
Deletes a directory, including its contents.
/*****
*@dir – Directory to destroy
*@virtual[optional]- whether a virtual directory
*/
function destroyDir($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;
}
}
7. PHP parses JSON data
Same as most popular web services such as twitter provide data through open APIs , it always knows how to parse various transmission formats of API data, including JSON, XML, etc.
$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. PHP parses XML data
// xml string
$xml_string=”
Foo
foo@bar.com
Foobar
foobar@foo.com
”;
//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 $user->email, '
';
}
9. PHP creates log abbreviation
Create user-friendly logs Abbreviation.
function create_slug($string){
$slug=preg_replace('/[^A-Za-z0-9-]+/', '-', $string);
return $slug;
}
10 . PHP gets the real IP address of the client
This function will get the real IP address of the user, even if he uses a proxy server.
function getRealIpAddr()
{
if (!emptyempty($_SERVER['HTTP_CLIENT_IP']))
{
$ip=$_SERVER['HTTP_CLIENT_IP'];
}
elseif (!emptyempty($_SERVER['HTTP_X_FORWARDED_F OR ']))
//to check ip is pass from proxy
{
$ip=$_SERVER['HTTP_X_FORWARDED_FOR'];
}
else
{
$ip=$_SERVER['REMOTE_ADDR'];
}
return $ip;
}
11. PHP mandatory file download
provides users with mandatory file download function.
/********************
*@file – path to file
*/
function force_download($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 creates tag cloud
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[] = '. '" href="#" title="" . $tag .
'' returned a count of ' . $count . '">'
. htmlspecialchars( stripslashes( $tag ) ) . '';
}
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 search Similarity of two strings
PHP provides a rarely used similar_text function, but this function is very useful for comparing two strings and returning the percentage of similarity.
similar_text($string1, $string2, $percent);
//$percent will have the percentage of similarity
14. PHP uses Gravatar in applications Universal avatar
As WordPress becomes more and more popular, Gravatar also Then it became popular. Since Gravatar provides an easy-to-use API, incorporating it into your application becomes easy.
/******************
*@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, $rating)
{
echo ''&default='.$default.'&size='.$size.'&rating= '.$rating.'" width="'.$size.'px"
height="'.$size.'px" />';
}
15. PHP truncates text at character breakpoints
The so-called word break is where a word can be broken when changing lines. This function will truncate the string at the word break.
// 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. 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’;
}
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['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 = eregi_replace(‘(((f|ht)lianqiangjavatp://)[-a-zA-Z0-9@:%_+.~#?&//=]+)’,
‘1’, $text);
$text = eregi_replace(‘([[:space:]()[{}])(www.[-a-zA-Z0-9@:%_+.~#?&//=]+)’,
‘12’, $text);
$text = eregi_replace(‘([_.0-9a-z-]+@([0-9a-z][0-9a-z-]+.)+[a-z]{2,3})’,
‘1’, $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 $im2;
}
21. PHP检测 ajax 请求
大多数的 JavaScript 框架如 jquery，Mootools 等，在发出 Ajax 请求时，都会发送额外的 HTTP_X_REQUESTED_WITH 头部信息，头当他们一个ajax请求，因此你可以在服务器端侦测到 Ajax 请求。
if(!emptyempty($_SERVER['HTTP_X_REQUESTED_WITH']) && strtolower($_SERVER['HTTP_X_REQUESTED_WITH']) == ‘xmlhttprequest’){
//If AJAX Request Then
}else{
//something else
}

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