How to get the file name under a folder?

Suppose I have a directory look like:

ABC
|_ a1.txt
|_ a2.txt
|_ a3.txt
|_ a4.txt
|_ a5开发者_开发知识库.txt

How can I use PHP to get these file names to an array, limited to a specific file extension and ignoring directories?

You can use the glob() function:

Example 01:

<?php
  // read all files inside the given directory
  // limited to a specific file extension
  $files = glob("./ABC/*.txt");
?>

Example 02:

<?php
  // perform actions for each file found
  foreach (glob("./ABC/*.txt") as $filename) {
    echo "$filename size " . filesize($filename) . "\n";
  }
?>

Example 03: Using RecursiveIteratorIterator

<?php 
foreach(new RecursiveIteratorIterator( new RecursiveDirectoryIterator("../")) as $file) {
  if (strtolower(substr($file, -4)) == ".txt") {
        echo $file;
  }
}
?>

Try this:

if ($handle = opendir('.')) {
    $files=array();
    while (false !== ($file = readdir($handle))) {
        if(is_file($file)){
            $files[]=$file;
        }
    }
    closedir($handle);
}

scandir lists files and directories inside the specified path.

Here is the most Efficient way based on this article's benchmarks:

function getAllFiles() {
    $files = array();
    $dir = opendir('/ABC/');
    while (($currentFile = readdir($dir)) !== false) {
        if (endsWith($currentFile, '.txt'))
            $files[] = $currentFile;
    }
    closedir($dir);
    return $files;
}

function endsWith($haystack, $needle) {
    return substr($haystack, -strlen($needle)) == $needle;
}

just use the getAllFiles() function, and you can even modify it to take the folder path and/or the extensions needed, it is easy.

Aside from scandir (@miku), you might also find glob interesting for wildcard matching.

If your text files is all that you have inside of the folder, the simplest way is to use scandir, like this:

<?php
$arr=scandir('ABC/');
?>

If you have other files, you should use glob as in Lawrence's answer.

$dir = "your folder url"; //give only url, it shows all folder data

if (is_dir($dir)){
    if ($dh = opendir($dir)){
        while (($file = readdir($dh)) !== false){
            if($file != '.' and $file != '..'){
                echo $file .'<br>';
            }
        }
        closedir($dh);
    }
}

output:

xyz
abc
2017
motopress