How to Work with Files/Folders in PHP

PHP, being a server-side language, offers convenient access to the filesystem. In this blog post, we will explore some basic operations on files and folders using PHP.

Checking if a File Exists

To check if a file exists, we can use the file_exists() function like this:

file_exists('test.txt'); // true

Getting the Size of a File

To get the size of a file, we can use the filesize() function:

filesize('test.txt');

Opening a File

To open a file, we can use the fopen() function. In the following example, we open the file test.txt in read-only mode and store the file descriptor in the variable $file:

$file = fopen('test.txt', 'r');

Remember to close the file after you are done using it by calling fclose($fd).

Reading the Content of a File

To read the content of a file into a variable, we can use fread() or fgets(). Here are two examples:

$file = fopen('test.txt', 'r');
$content = fread($file, filesize('test.txt'));

$file = fopen('test.txt', 'r');
$content = '';
while (!feof($file)) {
  $content .= fgets($file, 5000);
}

The feof() function is used to check if we have reached the end of the file, and fgets() reads 5000 bytes at a time.

Reading a File Line by Line

If you want to read a file line by line, you can use the fgets() function in a loop:

$file = fopen('test.txt', 'r');
while(!feof($file)) {
  $line = fgets($file);
  // do something with the line
}

Writing to a File

To write to a file, you need to open it in write mode and then use the fwrite() function:

$data = 'test';
$file = fopen('test.txt', 'w');
fwrite($file, $data);
fclose($file);

Deleting a File

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

unlink('test.txt');

These are the basics of working with files and folders in PHP. Of course, there are many more functions available in the PHP filesystem documentation for more advanced operations.