Home >Backend Development >PHP Tutorial >21 Life-saving PHP Codes_PHP Tutorial
21 Life-saving PHP Codes_PHP Tutorial
- WBOYOriginal
- 2016-07-13 17:46:42980browse
1. PHP can read random strings
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 $password;
}
2. PHP generates a random string
If you do not need a readable string, use this function instead to create a random string as the user's random password, etc.
2. PHP generates a random string
If you do not need a readable string, use this function instead to create a random string as the user's random password, etc.
/*************
*@l - length of random string
*/
function generate_rand($l){
$c= "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789";
srand((double)microtime()*1000000);
for($i=0; $i<$l; $i++) {
$rand.= $c[rand()%strlen($c)];
}
return $rand;
}
3. PHP encoded email address
Using this code, any email address can be encoded as an html character entity to prevent it from being collected by spam programs.
function encode_email($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 = '';
$part4 = '';
$encoded = '';
return $encoded;
}
4. PHP verification email address
Email verification is perhaps the most commonly used web form verification in China. In addition to verifying the email address, this code can also choose to check the MX record in the DNS to which the email domain belongs, making the email verification function more powerful.
function is_valid_email($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, $mxrecords);
}
else
Else
return false;
}
5. PHP列出目录内容
function list_files($dir)
{
if(is_dir($dir))
{
if($handle = opendir($dir))
{
while(($file = readdir($handle)) !== false)
{
if($file != "." && $file != ".." && $file != "Thumbs.db")
{
echo ''.$file.'
'."n";
}
}
closedir($handle);
}
}
}
6. PHP destroy directory
Delete a directory, including its contents.
/*****
*@dir - Directory to destroy
*@virtual[optional]- whether a virtual directory
*/
function destroyDir($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 == '.' || $file == '..')
elseif (is_dir($dir.$ds.$file))
destroyDir($dir.$ds.$file);
Since
Since
}
closedir($handle);
rmdir($dir);
return true;
}
Else {
return false;
}
}
7. PHP parses JSON data
As most popular web services such as twitter provide data through open APIs, it always knows how to parse API data in various delivery formats, 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="
& Lt; email & gt; fobar@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 $user->email, '
';
}
9. PHP creates log abbreviation
Create user-friendly log abbreviations.
function create_slug($string){
$slug=preg_replace('/[^A-Za-z0-9-]+/', '-', $string);
return $slug;
}
10. Get the real IP address of the client with PHP
This function will get the user's real IP address, even if he uses a proxy server.
function getRealIpAddr()
{
If (!emptyempty($_SERVER['HTTP_CLIENT_IP']))
{
$ip=$_SERVER['HTTP_CLIENT_IP'];
}
elseif (!emptyempty($_SERVER['HTTP_X_FORWARDED_FOR']))
//to check ip is pass from proxy
{
$ip=$_SERVER['HTTP_X_FORWARDED_FOR'];
}
Else
{
$ip=$_SERVER['REMOTE_ADDR'];
}
return $ip;
}
11. PHP mandatory file download
Provide users with a mandatory file download function.
/********************
*@file - path to file
*/
function force_download($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. Create tag cloud with 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;
foreach( $data as $tag => $count )
{
$size = $minFontSize + ( $count - $minimumCount )
* ( $maxFontSize - $minFontSize ) / $spread;
$cloudTags[] = ''
. 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 finds similarity between two strings
PHP provides a rarely used, but very useful, similar_text function that compares two strings and returns a percentage of how similar they are.
similar_text($string1, $string2, $percent);
//$percent will have the percentage of similarity
As WordPress becomes more and more popular, so does Gravatar. 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, $rating)
{
echo '.<br />
'&default='.$default.'&size='.$size.'&rating='.$rating.')
}
The so-called word break is the place where a word can be broken when changing lines. This function will truncate the string at hyphenation points.
The so-called word break is the place where a word can be broken when changing lines. This function will truncate the string at hyphenation points.
15. PHP truncates text at character breakpoints
The so-called word break is a place where a word can be broken when changing lines. This function will truncate the string at hyphenation points.
// 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 file Zip compression
/* 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);
/* 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 decompresses Zip files /********************** *@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'; . if (!preg_match("/^(http|ftp):/", $_POST['url'])) { $_POST['url'] = 'http://'.$_POST['url']; } 19. PHP converts URL string into hyperlink
This function converts URL and email address strings into clickable hyperlinks.
function makeClickableLinks($text) {
$text = eregi_replace('(((f|ht){1}tp://)[-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 $text;
}
20. PHP adjust image size
Creating image thumbnails takes a lot of time, this code will help to understand the logic of thumbnails.
/**********************
*@filename - path to the image
*@tmpname - temporary path to thumbnail
*@xmax - max width
*@ymax - max height
*/
function resize_image($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
}