PHP Filesystem fopen() Function

---

---

The PHP Filesystem fopen() function is used to open a file or URL. If it fails, it can return false and an error on failure. We can hide the error output by adding an '@' in front of the function name. The fopen() function can bind named resource specified by filename to a stream.

Syntax

Below is the syntax of the PHP Filesystem fopen() function −

resource fopen ( string $filename , string $mode [, bool $use_include_path = FALSE [, resource $context ]] )

Parameters

Here are the required and optional parameters of the fopen() function −

Return Value

It returns a resource handle if the file was successfully opened, or FALSE on failure.

PHP Version

The fopen() function was first introduced as part of core PHP 4 and work well with the PHP 5, PHP 7, PHP 8.

Example

In the below code we will see basic usage of the PHP Filesystem fopen() function like how we can open the file and read that file, how we can write in the file after opening.

<?php
   $file = fopen("/PhpProject/sample.txt", "r");
   $file = fopen("/PhpProject/index.php", "r");
   $file = fopen("/PhpProject/sample1.txt", "wb");
?>

Example

In the below PHP code, we will open a file called "myfile.txt" in read mode ("r") using fopen() function. And we will use if-else statement to check whether the file is opened or not. Also we read the file line by line until we reach the end of it with the help of a while loop and fgets().

<?php
   $file = fopen("/PhpProject/myfile.txt", "r");
   if ($file) {
      while (($line = fgets($file)) !== false) {
         echo $line;
      }
      fclose($file);
   } else {
      echo "Failed to open file.";
   }
?> 

Output

This will produce the following result −

This is a sample file.

Example

In this example we will use fopen() to open or create a file called "newfile.txt" in writing mode w.

<?php
   $file = fopen("newfile.txt", "w");
   if ($file) {
      fwrite($file, "Hello, world!");
      fclose($file);
      echo "Data written to file.";
   } else {
      echo "Failed to open file.";
   }
?> 

Output

This will lead to the following outcome −

Data written to file.

Example

In this example we will use fopen() to open or create a file called "log.txt" in append mode "a". If the file is successfully opened or created so we will use fwrite() to append the string to the file.

<?php
   $file = fopen("log.txt", "a");
   if ($file) {
      fwrite($file, "New log entry");
      fclose($file);
      echo "New entry added to log file.";
   } else {
      echo "Failed to open file.";
   }
?> 

Output

This will generate the below result −

New entry added to log file.

Note

Checking whether fopen() gives false is important to handle issues correctly. Always use fclose() to close the file handle and release resources after you have completed any file operations.

Summary

The fopen() function in PHP can be used to open files and URLs. Programmers can add, read from, and write to files with the help of this flexible function to work with Filesystems.