PHP File Handling

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PHP offers a wide range of functions and features for handling files and directories. In this guide, I'll cover basic file handling operations such as reading and writing files, working with directories, and handling file uploads.

Reading Files

Reading a File Line by Linephpy code

$file = fopen("example.txt", "r"); // Open the file for reading

if ($file) {

    while (($line = fgets($file)) !== false) {

        echo $line; // Process each line

    }

    fclose($file); // Close the file when done

} else {

    echo "Unable to open file!";

}

Reading the Entire File

php code

$file_contents = file_get_contents("example.txt"); // Read the entire file

echo $file_contents;

Writing Files

Writing to a File

php code

$data = "Hello, World!";

$file = fopen("example.txt", "w"); // Open the file for writing (creates if not exists)

if ($file) {

    fwrite($file, $data); // Write data to the file

    fclose($file); // Close the file

    echo "Data written successfully!";

} else {

    echo "Unable to open file for writing!";

}

Working with Directories

Creating a Directory

php code

$dir_name = "new_directory";

if (!is_dir($dir_name)) {

    mkdir($dir_name); // Create a new directory

    echo "Directory created!";

} else {

    echo "Directory already exists!";

}

Listing Files in a Directory

php code

$dir = "/path/to/directory";

$files = scandir($dir); // Returns an array of filenames

foreach ($files as $file) {

    echo $file . "<br>";

}

File Uploads

To handle file uploads in PHP, you typically use a form with enctype="multipart/form-data" and access the uploaded file information using the $_FILES superglobal.

HTML Form

html code

<form action="upload.php" method="post" enctype="multipart/form-data">

    <input type="file" name="file_to_upload">

    <input type="submit" value="Upload">

</form>

PHP File (upload.php)

php code

$target_dir = "uploads/"; // Directory where uploaded files will be stored

$target_file = $target_dir . basename($_FILES["file_to_upload"]["name"]);

$uploadOk = 1;

// Check if the file already exists

if (file_exists($target_file)) {

    echo "File already exists.";

    $uploadOk = 0;

}

// Check file size

if ($_FILES["file_to_upload"]["size"] > 500000) {

    echo "File is too large.";

    $uploadOk = 0;

}

// Upload the file

if ($uploadOk == 1) {

    if (move_uploaded_file($_FILES["file_to_upload"]["tmp_name"], $target_file)) {

        echo "The file " . basename($_FILES["file_to_upload"]["name"]) . " has been uploaded.";

    } else {

        echo "There was an error uploading your file.";

    }

}

This is a basic overview of file handling in PHP, including reading and writing files, working with directories, and handling file uploads. Be sure to perform additional validation and security checks when working with user-uploaded files to ensure the security of your application.

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