What is the code to retrieve files from a folder in PHP?

To retrieve all files within a folder using PHP, you can use the `glob()` or `scandir()` functions. Below are example codes for both methods:

1. glob()function

The `glob()` function accepts a single parameter and returns an array containing all files and directories that match the specified pattern. To retrieve all files in a directory, you can use the following code:

$files = glob('/path/to/folder/*');
foreach ($files as $file) {
    echo $file . '<br>';
}

In the above code, '/path/to/folder/' is the path to the directory you wish to search within. The wildcard '*' represents all files and subdirectories that you want to match. Then, we use a foreach loop to iterate over this array and output each file name.

2. `scandir()` function

The `scandir()` function returns an array containing all files and folders in a specified directory. You can use the following example code to retrieve all files from a directory:

$files = scandir('/path/to/folder/');
foreach ($files as $file) {
    if ($file != '.' && $file != '..') { // 忽略“.”和“..”目录
        echo $file . '<br>';
    }
}

In the above code, '/path/to/folder/' is the path to the directory you wish to search through. We use a foreach loop to iterate over this array and an if statement to ignore the filenames of the current directory and its parent directory ('.' and '..', respectively). Then, we output all remaining filenames.

In summary, using either the `glob()` or `scandir()` function to retrieve all files in a directory is relatively straightforward, and both methods can meet this requirement. Please choose the approach that best suits your specific use case.