Handy PHP Code Snippets

1. Human Readable Random String

This code will create a human readable string that will look more close to dictionary words, useful for captchas.
view plaincopy to clipboardprint?

/**************
*@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. Generate a Random String

If you don’t need human readable string, then use this function instead, which will create a random string you can use for user id’s etc.
view plaincopy to clipboardprint?

/*************
*@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. Encode Email Address

With this snippet, you can encode any email address into HTML entities so that spam bots do not find it.
view plaincopy to clipboardprint?

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. Validate email Address

E-mail validation is perhaps the most used validation in web forms, this code will validate email address and also optionally check the MX records of the domain provided in email address to make email validation more robust.
view plaincopy to clipboardprint?

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. List Directory Contents

view plaincopy to clipboardprint?

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. Destroy Directory

Delete a directory including its contents.
view plaincopy to clipboardprint?

/*****
*@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

With most of the popular web services like Twitter providing their data through APIs, it is always helpful to know how to parse API data which is sent in various 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. Parse 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. Create Post Slugs

Create user friendly post slugs from title string to use within URLs.

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

10. Get Real IP Address of Client

This function will fetch the real IP address of the user even if he is behind a proxy server.

function getRealIpAddr()
{
if (!empty($_SERVER[‘HTTP_CLIENT_IP’]))
{
$ip=$_SERVER[‘HTTP_CLIENT_IP’];
}
elseif (!empty($_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. Force file Download

Provide files to the user by forcing them to download.

/********************
*@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. Creating a Tag Cloud

function getCloud( $data = array(), $minFontSize = 12, $maxFontSize = 30 )
{
$minimumCount = min($data);
$maximumCount = max($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. Find Similarity Between Two Strings

PHP includes a function similar_text very rarely used but quite useful that compares two strings and returns the percentage of similarity between two.

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

14. Use Gravatars in Your Application

With ever increasing popularity of WordPress, Gravatars have become quite popular. It is very easy to integrate them into your application as they provide a very easy to use API.

/******************
*@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, $rating)
{
echo ‘<img src=”http://www.gravatar.com/avatar.php?gravatar_id=&#8217;.md5($email).
‘&default=’.$default.’&size=’.$size.’&rating=’.$rating.'” width=”‘.$size.’px”
height=”‘.$size.’px” />’;
}

15. Truncate Text at Word Break

This function will truncate strings only at word breaks which can be used to show a teaser for complete article without breaking words.

// Original PHP code by Chirp Internet: http://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 Files on the Fly

/* 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);

Source: David Walsh

17. Unzip Zip File

/**********************
*@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. Prepend http to a URL

Some times you need to accept some url as input but users seldom add http:// to it, this code will add http:// to the URL if it’s not there.

if (!preg_match(“/^(http|ftp):/”, $_POST[‘url’])) {
$_POST[‘url’] = ‘http://&#8217;.$_POST[‘url’];
}

19. Convert URLs within String into hyperlinks

This function converts URLs and e-mail addresses within a string into clickable hyperlinks.

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. Resize Images on the fly

Creating thumbnails of the images is required many a times, this code will be useful to know about the logic of thumbnail generation.

/**********************
*@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. Detect AJAX Request

Most of the JavaScript frameworks like jQuery, mootools send and additional HTTP_X_REQUESTED_WITH header when they make an AJAX request, so that you can detect AJAX request on server side.(source)

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

21 Really Useful & Handy PHP Code Snippets

1. Human Readable Random String

This code will create a human readable string that will look more close to dictionary words, useful for captchas.
view plaincopy to clipboardprint?

/**************
*@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. Generate a Random String

If you don’t need human readable string, then use this function instead, which will create a random string you can use for user id’s etc.
view plaincopy to clipboardprint?

/*************
*@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. Encode Email Address

With this snippet, you can encode any email address into HTML entities so that spam bots do not find it.
view plaincopy to clipboardprint?

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. Validate email Address

E-mail validation is perhaps the most used validation in web forms, this code will validate email address and also optionally check the MX records of the domain provided in email address to make email validation more robust.
view plaincopy to clipboardprint?

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. List Directory Contents

view plaincopy to clipboardprint?

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. Destroy Directory

Delete a directory including its contents.
view plaincopy to clipboardprint?

/*****
*@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

With most of the popular web services like Twitter providing their data through APIs, it is always helpful to know how to parse API data which is sent in various 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. Parse 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. Create Post Slugs

Create user friendly post slugs from title string to use within URLs.

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

10. Get Real IP Address of Client

This function will fetch the real IP address of the user even if he is behind a proxy server.

function getRealIpAddr()
{
if (!empty($_SERVER[‘HTTP_CLIENT_IP’]))
{
$ip=$_SERVER[‘HTTP_CLIENT_IP’];
}
elseif (!empty($_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. Force file Download

Provide files to the user by forcing them to download.

/********************
*@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. Creating a Tag Cloud

function getCloud( $data = array(), $minFontSize = 12, $maxFontSize = 30 )
{
$minimumCount = min($data);
$maximumCount = max($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’
. ‘” class=”tag_cloud” 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. Find Similarity Between Two Strings

PHP includes a function similar_text very rarely used but quite useful that compares two strings and returns the percentage of similarity between two.

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

14. Use Gravatars in Your Application

With ever increasing popularity of WordPress, Gravatars have become quite popular. It is very easy to integrate them into your application as they provide a very easy to use API.

/******************
*@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, $rating)
{
echo ‘<img src=”http://www.gravatar.com/avatar.php?gravatar_id=&#8217;.md5($email).
‘&default=’.$default.’&size=’.$size.’&rating=’.$rating.'” width=”‘.$size.’px”
height=”‘.$size.’px” />’;
}

15. Truncate Text at Word Break

This function will truncate strings only at word breaks which can be used to show a teaser for complete article without breaking words.

// Original PHP code by Chirp Internet: http://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 Files on the Fly

/* 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);

Source: David Walsh
17. Unzip Zip File

/**********************
*@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. Prepend http to a URL

Some times you need to accept some url as input but users seldom add http:// to it, this code will add http:// to the URL if it’s not there.

if (!preg_match(“/^(http|ftp):/”, $_POST[‘url’])) {
$_POST[‘url’] = ‘http://&#8217;.$_POST[‘url’];
}

19. Convert URLs within String into hyperlinks

This function converts URLs and e-mail addresses within a string into clickable hyperlinks.

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. Resize Images on the fly

Creating thumbnails of the images is required many a times, this code will be useful to know about the logic of thumbnail generation.

/**********************
*@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. Detect AJAX Request

Most of the JavaScript frameworks like jQuery, mootools send and additional HTTP_X_REQUESTED_WITH header when they make an AJAX request, so that you can detect AJAX request on server side.(source)

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

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: