Conditional regex php - php

Question

I'm facing some problem with php regex but after many researches (conditional regex, subpattern regex), I still can't solve it.
I have a folder that contains many images and based on variable value I have to go to that folder and select all images that match the value.
e.g: In my folder I have 3 images:
p102.jpg ; p1020.jpg ; p102_1.jpg;
I only want the regex to select :
p102.jpg ; p102_1.jpg
but with the regex below It selects all 3 images.
$image_to_find = 102;
$path = "[^\d]*.*/"
$test = "/^[a-zA-Z]?$image_to_find".$path;
foreach(glob($file_directory) as $file){
if(preg_match($test, $file)){
match[]= $file;
}
}
I also try:
$path = "(?:\_[0-9]?).*/"; (it selects only p102_1.jpg)
Can you help me to figure it out. thanks
(sorry for the english)

Answer 1

You can avoid the foreach loop if you use the glob pattern:
$num = 102;
$result = glob($path . '[a-zA-Z]' . $num . '[._]*');
Note: if you need to allow several different formats, you can use array_merge and several glob patterns: array_merge(glob(...), glob(...));
If you want the first letter optional:
$result = array_merge(
glob($path . $num . '[._]*jpg'),
glob($path . '[a-zA-Z]' . $num . '[._]*jpg')
);
or better, use the brace option:
$result = glob($path . '{[a-zA-Z],}' . $num . '[._]*jpg', GLOB_BRACE);
That stays a better alternative than the combo "foreach/preg_match" (or preg_grep) if filenames are not too complicated.
With preg_grep:
$pattern = '~(?:^|/)[a-z]?' . $num . '(?:_\d+)?\.jpg$~i';
$result = preg_grep($pattern, glob($path . '*' . $num . '*.jpg'));

Answer 2

Try this:
/p102[_\.]\d*\.?jpg/g
https://regex101.com/r/hM4oE0/1
Where p102 should be your 'image_to_find' var.

Answer 3

Not tested, should work.
$find = 102;
$pattern = "/p". $find ."(?:_\d+)?\.jpg/";
$list = array();
foreach (glob($file_directory) as $file)
{
if (preg_match($pattern, $file))
{
$list[] = $file;
}
}
regex: http://regexr.com/3bp29

Answer 4

Tested and working:
<?php
$image_to_find = 102;
$pattern = '[a-zA-Z]' . $image_to_find . '[._]*';
$path = '/your_folder/your_subfolder/';
$file_directory = glob($path . $pattern );
echo '<pre>';
var_dump($file_directory);
echo '</pre>';
exit();
I hope this helps!