Basics of File Handling

File handling in PHP is similar as file handling is done by using any programming language like C.

Checking Whether a File Exists

To determine whether a file already exists, you can use the file_exists function, which returns either TRUE or FALSE and is used like this

			
					if (file_exists("testfile.txt")) echo "File exists";

Creating a File

At this point, testfile.txt doesn’t exist, so let’s create it an write.

			
					<?php // testfile.php
($fh = fopen("testfile.txt", "w")) or die("Failed to create file");
$text = <<<_END
Line 1
Line 2
Line 3
_END;
fwrite($fh, $text) or die("Could not write to file");
fclose($fh);
echo "File 'testfile.txt' written successfully";
?>

file handling functions in php

Always start by opening the file. You do this through a call to fopen.

fwrite to write to the file ( fwrite).

You can also read from an existing file ( fread or fgets) and do other things.

Finish by closing the file ( fclose).You should clean up by closing the file when you’re finished.

Reading from Files

The easiest way to read from a text file is to grab a whole line through fgets.

Reading a file with fgets

			
					<?php
($fh = fopen("testfile.txt", "r")) or
    die("File does not exist or you lack permission to open it");
$line = fgets($fh);
fclose($fh);
echo $line;
?>

Reading a file with fread

			
					<?php
($fh = fopen("testfile.txt", "r")) or
    die("File does not exist or you lack permission to open it");
$text = fread($fh, 3);
fclose($fh);
echo $text;
?>

The fread function is commonly used with binary data.

Copying Files

PHP copy function to create a clone of testfile.txt

			
					<?php
 copy('testfile.txt', 'testfile2.txt') or die("Could not copy file");
 echo "File successfully copied to 'testfile2.txt'";
?>

Moving a File

To move a file, rename it with the rename function

			
					<?php
 if (!rename('testfile2.txt', 'testfile2.new'))
 echo "Could not rename file";
 else echo "File successfully renamed to 'testfile2.new'";
?>

You can use the rename function on directories, too.

Deleting a File

Deleting a file is just a matter of using the unlink function to remove it from the file‐system.

			
					<?php
 if (!unlink('testfile2.new')) echo "Could not delete file";
 else echo "File 'testfile2.new' successfully deleted";
?>

PHP | File Handling