How to Write into a File in PHP

  1. Using file_put_contents() function to write into a file in PHP
  2. Using fopen(), fwrite() and fclose() functions to write into a file in PHP

In this article, we will introduce methods to write into a file in PHP.

  • Using file_put_contents() function
  • Using fopen(), fwrite() and fclose() functions

Using file_put_contents() function to write into a file in PHP

The built-in function file_put_contents() writes the data into a file in PHP. It searches for the file to write in, and if the desired file is not present, it creates a new file. We can use this function to write into a file. The correct syntax to use this function is as follows.

file_put_contents($pathOfFile, $info, $customContext, $mode);

This function accepts four parameters. The detail of these parameters is as follows.

Parameter Description
$pathOfFile mandatory Path of the file.
$info mandatory Data to write in a file. It can be a string.
$customContext optional Specify a custom context.
$mode optional The mode in which the data will be written on the file.
It can be FILE_USE_INCLUDE_PATH, FILE_APPEND, and LOCK_EX.

This function returns the number of bytes written on the file if successful, or False if it fails.

The following program will write the data into a file.

<?php 
$data = "This is a program";
$bytes = file_put_contents("myfile.json", $data); 
echo "The number of bytes written is $bytes.";
?>

Output:

The number of bytes written is 17.

Using fopen(), fwrite() and fclose() functions to write into a file in PHP

The built-in functions fopen(), fwrite() and fclose() are used to open a file, write into a file and close a file. The correct syntax to use these functions is as follows

fopen($fileName, $mode, $path, $context);

This function has four parameters, and their details are as follows.

Parameters Description
$fileName mandatory It is the name of the file to open.
$mode mandatory It is the mode of the file. There are several modes, check here.
$path optional It is the path to search file.
$context optional It is used to set the context of the file.

The possible modes include,

mode Description
r Read only
r+ Read and write
w Write only. If the file does not exist, attempt to create it.
w+ Read and write. If the file does not exist, attempt to create it.
a Append.
a+ Read and append.
x Create and write only.
x+ Create and read and write
fwrite($fileName, $info, $length);

It has three parameters. The details of its parameters are as follows.

Parameter Description
$fileName mandatory It is the file to write in.
$info mandatory It is the information that will be written in the file.
$length optional It is the number of bytes to be written in the file.
fclose($fileName);

This function accepts only one parameter that is the name of the file to be closed. It returns TRUE on success and FALSE on failure.

The below program writes the data into a file.

<?php 
$myfile = fopen("myfile.txt", "w"); 
$bytes = fwrite($myfile, "This is a program"); 
fclose($myfile); 
echo "The number of bytes written is $bytes.";
?>

Here the mode in fopen() function is set to w that means the file is opened for writing only.

Output:

The number of bytes written is 17.
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