Working with files and directories is one of the most important tasks in PHP. Whether you are uploading files, reading configuration data, generating reports, creating backups, or managing logs—PHP provides powerful functions to handle everything.

This guide explains how files and folders work, how PHP interacts with them, and real-world use cases, all in a clear and practical way.

⭐ What Are Files & Directories in PHP?

Files

A file stores data such as:

Text
JSON
Images
PDFs
Logs
Configurations

PHP can create, read, write, delete, move, and upload files easily.

Directories (Folders)

Directories help you organize files. PHP can:

Create folders
Scan directories
List files
Delete directories
Move files to other folders

Understanding PHP’s file and directory handling helps you build powerful applications.

⭐ Understanding File Paths in PHP

PHP works with two types of paths:

1. Absolute Path

Full path from your server root.

Example:
/var/www/html/project/images/logo.png
or on Windows:
C:/xampp/htdocs/project/data.txt

2. Relative Path

Starts from the current file location.

Examples:

images/logo.png
../config/settings.php

Relative paths are common in real projects.

⭐ Checking If a File Exists

if (file_exists("data.txt")) {
    echo "File found!";
} else {
    echo "File not found.";
}

Useful for preventing errors.

⭐ Reading a File in PHP

1. Quick Read (One Line)

$content = file_get_contents("data.txt");
echo $content;

2. Traditional Read Method

$handle = fopen("data.txt", "r");
echo fread($handle, filesize("data.txt"));
fclose($handle);

⭐ Writing to a File

Rewrite the file

file_put_contents("log.txt", "New log entry");

Append data to a file

file_put_contents("log.txt", "New entry\n", FILE_APPEND);

Used for:

Logs
Form submissions
Storing temporary data

⭐ Creating a New File

$handle = fopen("newfile.txt", "w");
fwrite($handle, "Hello World!");
fclose($handle);

⭐ Deleting a File

unlink("oldfile.txt");

⭐ Working with Directories

Create a Directory

mkdir("uploads");

Check if Directory Exists

if (is_dir("uploads")) {
    echo "Directory exists!";
}

Remove a Directory

rmdir("oldfolder");

(Folder must be empty.)

⭐ Scanning a Directory (List All Files)

$files = scandir("uploads");

print_r($files);

Output example:

Array
(
    [0] => .
    [1] => ..
    [2] => file1.jpg
    [3] => file2.png
)

Useful for:

File managers
Image galleries
Admin dashboards

⭐ Moving / Renaming Files

rename("oldname.txt", "newname.txt");

Or to move into another folder:

rename("file.txt", "archive/file.txt");

⭐ Getting File Information

echo filesize("data.txt");   // File size
echo filetype("data.txt");   // File type

⭐ Real-World Applications

✔ File upload systems
✔ Image gallery
✔ Log files for debugging
✔ Creating backups
✔ Reading JSON/XML files
✔ Managing folders for each user
✔ Generating printable reports

⭐ Best Practices

✔ Always check if files exist before accessing them
✔ Use correct permissions (read, write, execute)
✔ Never trust uploaded files — validate them
✔ Avoid using absolute paths when possible
✔ Close file handles to avoid memory leaks
✔ Use folders to organize and separate logic

Citations

🔗 View other articles about PHP:
http://savanka.com/category/learn/php/

🔗 External PHP Documentation:
https://www.php.net/manual/en/

What Are Files & Directories in PHP? See Examples