Collection of some practical custom functions in PHP

Although PHP comes with powerful function libraries, in many cases, we also have to write custom functions to implement some functions and requirements. The following are some useful custom functions that can solve common requirements, such as converting URL strings into hyperlink, listing directory content, and verifying email addresses, this page can be added to favorites for later reading ~

1. PHP can read random strings

This Code creates a readable string that is closer to a word in the dictionary and is practical and password-verified.

/************** *@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 readable strings, use this function instead to create a random string as your random password.

/************* *@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

This code can be used to encode any email address as an html character entity to prevent 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 = '<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 verification email address

Email verification may be the most common web form verification. In addition to verifying the email address, this code can also choose to check MX records in the DNS to which the email domain belongs, making email verification 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 listing directory content

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 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 == '.' || $file == '..')             {                 continue;             }             elseif (is_dir($dir.$ds.$file))             {                 destroyDir($dir.$ds.$file);             }             else             {                 unlink($dir.$ds.$file);             }         }         closedir($handle);         rmdir($dir);         return true;     }     else     {         return false;     } } 

7. parse JSON data in PHP

Like most popular Web services, such as twitter, which provides data through open APIs, it always knows how to parse various transfer formats of API data, including JSON and XML.

$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="<?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. Name scaling of PHP creation logs

Create a user-friendly log scaling name.

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

10. PHP obtains the real IP address of the client.

This function will obtain the real IP address of the user, even if he uses the 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

It provides users with mandatory File Download functions.

/******************** *@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 a tag cloud in 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[] = '<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. Search for similarity between two strings in PHP

PHP provides a rarely used similar_text function, but this function is very useful for comparing two strings and returning a percentage of similarity.

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

14. Use the Gravatar profile picture in PHP applications

As WordPress becomes increasingly popular, Gravatar also becomes popular. Gravatar provides easy-to-use APIs, making it easy to include them in applications.

/****************** *@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 ''; } 

15. PHP truncates text at the character breakpoint

Word break refers to the place where a word can be broken when it is switched. This function truncates the string at the 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. Zip compression of PHP files

/* 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. decompress the Zip file in PHP.

/********************** *@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 presets the http string for the URL address

Sometimes you need to accept URL input in some forms, but few users add http: // fields. This code will add this field to the URL.

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

19. PHP converts the URL string into a hyperlink

This function converts the URL and e-mail address strings into clickable superlinks.

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. PHP adjusted image size

Creating image thumbnails takes a long time. This Code helps you understand the thumbnails logic.

/********************** *@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 detects ajax requests

Most JavaScript frameworks, such as jquery and Mootools, send additional HTTP_X_REQUESTED_WITH header information when sending Ajax requests. The header is an ajax request, therefore, you can detect Ajax requests on the server side.

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

22. Keyword highlighting

function highlight($sString, $aWords) {     if (!is_array ($aWords) || emptyempty ($aWords) || !is_string ($sString)) {         return false;     }      $sWords = implode ('|', $aWords);     return preg_replace ('@\b('.$sWords.')\b@si', '<strong style="background-color:yellow">$1</strong>', $sString); } 

23. Get your Feedburner user

function get_average_readers($feed_id,$interval = 7){     $today = date('Y-m-d', strtotime("now"));     $ago = date('Y-m-d', strtotime("-".$interval." days"));     $feed_url="https://feedburner.google.com/api/awareness/1.0/GetFeedData?uri=".$feed_id."&dates=".$ago.",".$today;     $ch = curl_init();     curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);     curl_setopt($ch, CURLOPT_URL, $feed_url);     $data = curl_exec($ch);     curl_close($ch);     $xml = new SimpleXMLElement($data);     $fb = $xml->feed->entry['circulation'];      $nb = 0;     foreach($xml->feed->children() as $circ){         $nb += $circ['circulation'];     }      return round($nb/$interval); } 

24. automatically generate Password

function generatePassword($length=9, $strength=0) {     $vowels = 'aeuy';     $consonants = 'bdghjmnpqrstvz';     if ($strength >= 1) {         $consonants .= 'BDGHJLMNPQRSTVWXZ';     }     if ($strength >= 2) {         $vowels .= "AEUY";     }     if ($strength >= 4) {         $consonants .= '23456789';     }     if ($strength >= 8 ) {         $vowels .= '@#$%';     }      $password = '';     $alt = time() % 2;     for ($i = 0; $i < $length; $i++) {         if ($alt == 1) {             $password .= $consonants[(rand() % strlen($consonants))];             $alt = 0;         } else {             $password .= $vowels[(rand() % strlen($vowels))];             $alt = 1;         }     }     return $password; } 

25. Compress multiple CSS files

header('Content-type: text/css'); ob_start("compress"); function compress($buffer) {   /* remove comments */   $buffer = preg_replace('!/\*[^*]*\*+([^/][^*]*\*+)*/!', '', $buffer);   /* remove tabs, spaces, newlines, etc. */   $buffer = str_replace(array("\r\n", "\r", "\n", "\t", '  ', '    ', '    '), '', $buffer);   return $buffer; }  /* your css files */ include('master.css'); include('typography.css'); include('grid.css'); include('print.css'); include('handheld.css');  ob_end_flush(); 

26. Get the short URL

function getTinyUrl($url) {     return file_get_contents("http://tinyurl.com/api-create.php?url=".$url); } 

27. Calculate the age based on the birthday

function age($date){     $year_diff = '';     $time = strtotime($date);     if(FALSE === $time){         return '';     }      $date = date('Y-m-d', $time);     list($year,$month,$day) = explode("-",$date);     $year_diff = date("Y") – $year;     $month_diff = date("m") – $month;     $day_diff = date("d") – $day;     if ($day_diff < 0 || $month_diff < 0) $year_diff–;      return $year_diff; } 

28. Computing execution time

//Create a variable for start time $time_start = microtime(true);  // Place your PHP/HTML/JavaScript/CSS/Etc. Here  //Create a variable for end time $time_end = microtime(true); //Subtract the two times to get seconds $time = $time_end - $time_start;  echo 'Script took '.$time.' seconds to execute'; 

29. PHP maintenance mode

function maintenance($mode = FALSE){     if($mode){         if(basename($_SERVER['SCRIPT_FILENAME']) != 'maintenance.php'){             header("Location: http://example.com/maintenance.php");             exit;         }     }else{         if(basename($_SERVER['SCRIPT_FILENAME']) == 'maintenance.php'){             header("Location: http://example.com/");             exit;         }     } } 

30. Prevent CSS styles from being cached

<link href="/stylesheet.css?<?php echo time(); ?>" rel="stylesheet" type="text/css" /&glt; 

31. Add st \ nd \ rd to the number

function make_ranked($rank) {     $last = substr( $rank, -1 );     $seclast = substr( $rank, -2, -1 );     if( $last > 3 || $last == 0 ) $ext = 'th';     else if( $last == 3 ) $ext = 'rd';     else if( $last == 2 ) $ext = 'nd';     else $ext = 'st';       if( $last == 1 && $seclast == 1) $ext = 'th';     if( $last == 2 && $seclast == 1) $ext = 'th';     if( $last == 3 && $seclast == 1) $ext = 'th';       return $rank.$ext; }