Using a random picture instead of a specific picture? - php

my current script is this:
$attach[] = array('pics/pic1.jpg', 'image/jpeg');
how can i change it, so it pics a random picture in the pics/ folder instead of a specified?
Theres like 20 pics in pics/
I want the script uses a random.

You can use array_rand() for this. If you don't already have all files in an array, you can easily do it with glob()
$all_pics = array();
foreach (glob("./pics/*") as $filename)
$all_pics[] = array($filename, filetype($filename));
$random_pic = array_rand($all_pics);
This is universal, if you are sure your pictures are all named pic1, pic2, etc., it is probably better to just generate a random number and use it as in sal00ms answer.

You can try something like this:
$attach[] = array('pics/pic'.rand(1,20).'.jpg', 'image/jpeg');
And rename your files pic1,pic2...,pic20

You may also try something like this
function getRandomImage()
{
// add more images in the array
$pics = array('pics/pic1.jpg', 'image/pic.jpeg', 'photo/pic.png');
$i = rand(0, count($pics)-1);
return $pics[$i];
}
$image = getRandomImage();

First generate a random number!
$random_number = rand(0, 19);
Then, get all the pics of the folder in an array.
$pics = glob("pics/*");
Then, get the random pic from the array using random number
$random_pic = $pics[$random_number];
You can simplify it in one step as
$random_pic = glob("pics/*")[rand(0, 19)];

Related

Random image from directory with no repeats?

I am successfully able to get random images from my 'uploads' directory with my code but the issue is that it has multiple images repeat. I will reload the page and the same image will show 2 - 15 times without changing. I thought about setting a cookie for the previous image but the execution of how to do this is frying my brain. I'll post what I have here, any help would be great.
$files = glob($dir . '/*.*');
$file = array_rand($files);
$filename = $files[$file];
$search = array_search($_COOKIE['prev'], $files);
if ($_COOKIE['prev'] == $filename) {
unset($files[$search]);
$filename = $files[$file];
setcookie('prev', $filename);
}
Similar to slicks answer, but a little more simple on the session front:
Instead of using array_rand to randomise the array, you can use a custom process that reorders based on just a rand:
$files = array_values(glob($dir . '/*.*'));
$randomFiles = array();
while(count($files) > 0) {
$randomIndex = rand(0, count($files) - 1);
$randomFiles[] = $files[$randomIndex];
unset($files[$randomIndex]);
$files = array_values($files);
}
This is useful because you can seed the rand function, meaning it will always generate the same random numbers. Just add (before you randomise the array):
if($_COOKIE['key']) {
$microtime = $_COOKIE['key'];
else {
$microtime = microtime();
setcookie('key', $microtime);
}
srand($microtime);
This does means that someone can manipulate the order of the images by manipulating the cookie, but if you're okay with that this this should work.
So you want to have no repeats per request? Use session. Best way to avoid repetitions is to have two arrays (buckets). First one will contains all available elements that your will pick from. The second array will be empty for now.
Then start picking items from first array and move them from 1st array to the second. (Remove and array_push to the second). Do this in a loop. On the next iteration first array won't have the element you picked already so you will avoid duplicates.
In general. Move items from a bucket to a bucket and you're done. Additionally you can store your results in session instead of cookies? Server side storage is better for that kind of things.

How to show 1 element of array dynamically with php?

in "file.txt" i have some numbers like 1234,123456,12345678 etc.
so i was wondering how i can get dynamically just one element, for example echo just 12345,then echo 123456, but one by one ???when user comes i want to show him one element,and then next time i want to show another element on the page, it would be good also if i could erase elements that i have echo...When i manually enter position it works... Please help...
I have a following code:
function test($n){
$file=file_get_contents("file.txt");
$array = explode(",", $file);
return print_r($array[$n]);
};
The solution will need deleting the number on your filesystem or marking it as already showed either on the filesystem or on the database, after the number gets echoed.
Shuffling the numbers or generating a random index will never quite be full proof since the same number could be shown again.
First of all, this is usually a terrible way of doing this.
It's much better to use a database, for example.
But you could do the following:
<?php
function getRandomNumber() {
// retrieve and parse the numbers
$numbers = file_get_contents('file.txt');
$numbers = explode(',' $numbers);
// select a random index
$randomIndex = array_rand($numbers);
// get the chosen number
$randomNumber = $numbers[$randomIndex];
// remove it from array
unset($numbers[$randomIndex]);
// save updated file
file_put_contents('file.txt', implode(',', $numbers));
return $randomNumber;
}

How to show a random picture in a web page?

My website has an image in a certain place and when a user reloads the page he should see a different image on the same place. I have 30 images and I want to change them randomly on every reload. How do I do that?
Make an array with the "picture information" (filename or path) you have, like
$pictures = array("pony.jpg", "cat.png", "dog.gif");
and randomly call an element of that array via
echo '<img src="'.$pictures[array_rand($pictures)].'" />';
Looks weird, but works.
The actual act of selecting a random image is going to require a random number. There are a couple of methods that can help with this:
rand() is used to generate a random number.
array_rand() is used to select a random element's index from an array.
You can think of the second function as a shortcut for using the first if you're specifically dealing with an array. So, for example, if you have an array of image paths from which to select the one you want to display, you can select a random one like this:
$randomImagePath = $imagePaths[array_rand($imagePaths)];
If you're storing/retrieving the images in some other way, which you didn't specify, then you may not be able to use array_rand() as easily. But, ultimately, you need to generate a random number. So some use of rand() would work for this.
If you store the information in your database, you can also SELECT a random image:
MySQL:
SELECT column FROM table
ORDER BY RAND()
LIMIT 1
PgSQL:
SELECT column FROM table
ORDER BY RANDOM()
LIMIT 1
Best,
Philipp
An easy way to create random images on popup is this method below.
(Note: You have to rename the images to "1.png", "2.png", etc.)
<?php
//This generates a random number between 1 & 30 (30 is the
//amount of images you have)
$random = rand(1,30);
//Generate image tag (feel free to change src path)
$image = <<<HERE
<img src="{$random}.png" alt="{$random}" />
HERE;
?>
* Content Here *
<!-- Print image tag -->
<?php print $image; ?>
This method is simple and I use this every time when I need a random image.
Hope this helps! ;)
I've recently written this which loads a different background on every pageload. Just replace the constant with the path to your images.
What it does is loop through your imagedirectory and randomly picks a file from it. This way you don't need to keep track of your images in an array or db or whatever. Just upload images to your imagedirectory and they will get picked (randomly).
Call like:
$oImg = new Backgrounds ;
echo $oImg -> successBg() ;
<?php
class Backgrounds
{
public function __construct()
{
}
public function succesBg()
{
$aImages = $this->_imageArrays( \constants\IMAGESTRUE, "images/true/") ;
if(count($aImages)>1)
{
$iImage = (int) array_rand( $aImages, 1 ) ;
return $aImages[$iImage] ;
}
else
{
throw new Exception("Image array " . $aImages . " is empty");
}
}
private function _imageArrays( $sDir='', $sImgpath='' )
{
if ($handle = #opendir($sDir))
{
$aReturn = (array) array() ;
while (false !== ($entry = readdir($handle)))
{
if(file_exists($sDir . $entry) && $entry!="." && $entry !="..")
{
$aReturn[] = $sImgpath . $entry ;
}
}
return $aReturn ;
}
else
{
throw new Exception("Could not open directory" . $sDir . "'" );
}
}
}
?>

Create Files Automatically using PHP script

I have a project that needs to create files using the fwrite in php. What I want to do is to make it generic, I want to make each file unique and dont overwrite on the others.
I am creating a project that will record the text from a php form and save it as html, so I want to output to have generated-file1.html and generated-file2.html, etc.. Thank you.
This will give you a count of the number of html files in a given directory
$filecount = count(glob("/Path/to/your/files/*.html"));
and then your new filename will be something like:
$generated_file_name = "generated-file".($filecount+1).".html";
and then fwrite using $generated_file_name
Although I've had to do a similar thing recently and used uniq instead. Like this:
$generated_file_name = md5(uniqid(mt_rand(), true)).".html";
I would suggest using the time as the first part of the filename (as that should then result in files being listed in chronological/alphabetic order, and then borrow from #TomcatExodus to improve the chances of the filename being unique (incase of two submissions being simultaneous).
<?php
$data = $_POST;
$md5 = md5( $data );
$time = time();
$filename_prefix = 'generated_file';
$filename_extn = 'htm';
$filename = $filename_prefix.'-'.$time.'-'.$md5.'.'.$filename_extn;
if( file_exists( $filename ) ){
# EXTREMELY UNLIKELY, unless two forms with the same content and at the same time are submitted
$filename = $filename_prefix.'-'.$time.'-'.$md5.'-'.uniqid().'.'.$filename_extn;
# IMPROBABLE that this will clash now...
}
if( file_exists( $filename ) ){
# Handle the Error Condition
}else{
file_put_contents( $filename , 'Whatever the File Content Should Be...' );
}
This would produce filenames like:
generated_file-1300080525-46ea0d5b246d2841744c26f72a86fc29.htm
generated_file-1300092315-5d350416626ab6bd2868aa84fe10f70c.htm
generated_file-1300109456-77eae508ae79df1ba5e2b2ada645e2ee.htm
If you want to make absolutely sure that you will not overwrite an existing file you could append a uniqid() to the filename. If you want it to be sequential you'll have to read existing files from your filesystem and calculate the next increment which can result in an IO overhead.
I'd go with the uniqid() method :)
If your implementation should result in unique form results every time (therefore unique files) you could hash form data into a filename, giving you unique paths, as well as the opportunity to quickly sort out duplicates;
// capture all posted form data into an array
// validate and sanitize as necessary
$data = $_POST;
// hash data for filename
$fname = md5(serialize($data));
$fpath = 'path/to/dir/' . $fname . '.html';
if(!file_exists($fpath)){
//write data to $fpath
}
Do something like this:
$i = 0;
while (file_exists("file-".$i.".html")) {
$i++;
}
$file = fopen("file-".$i.".html");

display random images without repetition

My name is Shruti.I'm new to php. I have a program which displays images randomly, there are about 200 images in my program.I want to display the random images with out repetition, can any one please help with this. here is my code.
Appreciate your help
Thank you.
I don't know whats about the $img_id but you could consider to use shuffle().
shuffle($file_array);
But then you loose the connection to $img_id. You could (I am not sure if this is the best solution), build your array this way:
$file_array = array(
array("images/bag200.bmp", 1),
array("images/bag178.bmp", 1),
array("images/bag004.bmp", 0,
...
);
In the long run, it is probably better to store all the image paths in a CSV file or even a database. Believe me, you don't want to maintain an array with > 200 entries manually ;)
You can loop over images this way (they are in random order now):
<?php foreach($file_array as $image): ?>
<img src="<?php echo $image ?>" />
<?php endforeach; ?>
If you only want to display a subset of the images, randomly chosen, you can do this:
$n = 20; // want to display 20 images
$rand = array_rand(range(0,200), $n); // draw keys randomly
shuffle($rand); //shuffle keys
foreach($rand as $r) {
echo '<img src="' . $file_array[$r] . '" />';
}
Some comments on your code:
$ran = array_rand($file_array);
$ran contains a key randomly chosen from the images.
for ($i=0;$i<200;$i++) {
//while (in_array($tst,$rand_array)){
$tst = $file_array[$ran];
$id = $img_id[$ran];//}
$rand_array[] = $tst;
$rand_id[] = $id;
}
You always pick the same entry from $file_array and $image_id because you never change $ran. That is way you get the same image 200 times.
If you want randomness but require uniqueness, you are looking for a quasi-random number generator. There are many different types with different properties. Look here for information on creating an algorithm: http://www.mathworks.nl/access/helpdesk/help/toolbox/stats/br5k9hi-8.html

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