PHP Filesystem file_get_contents() Function

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The PHP Filesystem file_get_contents() function is used to read a file into a string. This function is the preferred to read the contents of a file into a string because it can use memory mapping techniques if this is supported by the server to enhance performance.

This function is similar to file() function except that file_get_contents() function returns the file in a string starting at specified offset up to maxlen bytes.

Syntax

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

string file_get_contents ( string $filename [, bool $use_include_path = FALSE [, resource $context [, int $offset = 0 [, int $maxlen ]]]] )

Parameters

Here are the required and optional parameters of the file_get_contents function −

Return Value

It returns the file content as a string. If failed, it returns FALSE.

PHP Version

The file_get_contents() function is introduced as part of core PHP 4.3.0 and work well with the PHP 5, PHP 7, PHP 8.

Example

In this example we will use the PHP Filesystem file_get_contents() function to read a file and print the content of that file. So this is very basic usage of this function.

<?php
   // Path to the file
   $file = file_get_contents("/PhpProject/sample.txt", true);

   echo $file;
?>

Output

This will produce the following result −

tutorialspoint
tutorix

Example

This php code will show you how you can use optional parameters of file_get_contents() function and make the changes in the output content.

• In this we have used all the optional parameters.
• The first parameter is the file path.
• The second and third parameters, which are NULL, are optional and not used in this example.
• The fourth parameter - 4, is the starting point in the file. It will start reading from the 4th character.
• The fifth parameter - 10, is the length of the content to read. It will read 10 characters.

<?php
   // Define the file path here with optional parameters
   $section = file_get_contents("/PhpProject/sample.txt", NULL, NULL, 4, 10);
   var_dump($section);
?>

Output

This will generate the below result −

string(10) "rialspoint"

Example

In this PHP code we will see how we can handle the file error for example if the given file is not present in the directory. So if the file is not exist then we can show the error message to the user.

<?php
   // Assign path of the file
   $file_path = "/Applications/XAMPP/xamppfiles/htdocs/mac/non_existent.txt";

   // Use file_get_contents() function to get the content
   $content = file_get_contents($file_path);

   // Check file exists or not
   if ($content === FALSE) {
      echo "Error: Unable to read the file at $file_path";
   } else {
      var_dump($content);
   }
?> 

Output

This will create the below outcome −

Error: Unable to read the file at /Applications/XAMPP/xamppfiles/htdocs/mac/non_existent.txt

Example

In this example, our goal is to use a given URL (Uniform Resource Locator) as a file and get the content of that and echo it.

<?php
   // Reading a file from a URL
   $url = "https://www.example.com/sample.txt";

   // Get the content from the URL
   $content = file_get_contents($url);

   // Check the error 
   if ($content === FALSE) {
      echo "Error: Unable to read the file from the URL";
   } else {
      var_dump($content);
   }
?> 

Output

This will lead to the following outcome −

string(102) "This is a sample url to check that it works!"

Note

It is necessary to handle failures properly, particularly if working with files that might not be accessible or exist.

Summary

To read a file's contents into a string we can use PHP's file_get_contents() function. It has the ability to read the entire file or only specific sections of it. The function works well for basic file reading work, but for efficient operations, proper error handling needs to be implemented.