This chapter include following functions related to:

• Opening the files.
  
• Reading a file
  
• Writing a file
  
• Closing a file

Opening and closing files:                    

fopen() function is used to open a file, but in PHP same function is used to create a file. If you use fopen() on a file that does not exists, it will create that file. It has two parameter :

•   Name of the file
•   Mode of the file

There are six types of mode:

NOTE: After making the changes to the opened file the file must be close. It is mandatory to close the file. To close the file we use fclose() function.

Reading a File:

Once we open a file (using fopen()) it can be read by fread() function. This function has two parameter :

File pointer and the size of the file expressed in bytes.

Note: The length of the file can be determined by the filesize().

Following are the steps to read a file:

Step1: Open a file using fopen().

Step2: Get the file size using filesize().

Step 3: Read the file using fread().

Step 4: Close the file using fclose().

Create intro.txt file:

<?php

// fopen() will open a file intro.txt

$myfile = fopen("intro.txt", "r") or die("Unable to open file!");// if there is no file intro.txt it will give a message unable to open a file.

//’r’ is the read mode.

echo fread($myfile,filesize("intro.txt"));//filesize() will get the size of the file.

fclose($myfile);//fclose() will closed the file

?> 

<?php
$file = fopen("php.txt", "w") or die("Unable to open file!");
$text = "Neha singh\n";
fwrite($file, $text);
$text = "Rakesh singh\n";
fwrite($file, $text); //write the text on file.
fclose($file);
?>

<?php
$file = fopen("php.txt", "w") or die("Unable to open file!");
$text = "Arun garg\n";
fwrite($file, $text);
$text = "Raghu tandon \n";
fwrite($file, $text);
fclose($file);
?>