Working with Files and Directories in PHP

1. Opening and Closing Files

To work with files, you need to open them using the fopen() function. This function returns a file pointer resource that you can use to read from or write to the file:

$file = fopen("example.txt", "r"); // Open file for reading
if ($file) {
    // File operations go here
    fclose($file); // Close the file
}

2. Reading from Files

You can read the contents of a file using several functions:

• fgets(): Reads a line from the file.
• fread(): Reads a specified number of bytes from the file.
• file_get_contents(): Reads the entire file into a string.

$content = file_get_contents("example.txt");
echo $content; // Output the contents of the file

3. Writing to Files

You can write data to files using the following functions:

• fwrite(): Writes data to an open file.
• file_put_contents(): Writes data to a file, creating it if it doesn't exist.

$file = fopen("example.txt", "w"); // Open file for writing
fwrite($file, "Hello, World!");
fclose($file);

4. File Uploads

PHP allows you to handle file uploads through forms. Use the $_FILES superglobal to access uploaded file details:

<form action="upload.php" method="post" enctype="multipart/form-data">
    <input type="file" name="myfile">
    <input type="submit" value="Upload">
</form>
<?php
if (isset($_FILES['myfile'])) {
    $file = $_FILES['myfile'];
    move_uploaded_file($file['tmp_name'], "uploads/" . $file['name']);
    echo "File uploaded successfully!";
} ?>

5. Working with Directories

You can create, delete, and manipulate directories using PHP functions:

• mkdir(): Creates a new directory.
• rmdir(): Removes an empty directory.
• scandir(): Lists files and directories within a specified directory.

mkdir("new_directory"); // Create a new directory
$files = scandir("new_directory");
print_r($files); // List files in the directory

6. Deleting Files

To delete a file, use the unlink() function:

if (file_exists("example.txt")) {
    unlink("example.txt"); // Delete the file
    echo "File deleted successfully!";
}

7. Checking File and Directory Status

You can check the existence, permissions, and other properties of files and directories using various functions:

• file_exists(): Checks if a file or directory exists.
• is_readable(): Checks if a file is readable.
• is_writable(): Checks if a file is writable.

if (file_exists("example.txt")) {
    if (is_readable("example.txt")) {
        echo "File is readable.";
    }
}

8. Conclusion

Working with files and directories in PHP is essential for various applications. Understanding how to read, write, and manipulate files helps you create dynamic and interactive web applications.