File Handling In PHP

Introduction

In this blog, I will demonstrate how to read, write, and delete a file using PHP web programming language. Before we create, read, write, and delete a file, we need to understand some PHP functions and file modes carefully. These functions and modes are described below.

File modes

File modes specify the access type of your file.

Mode	Description
r	Open a file for reading only. File pointer starts at the beginning of the file.
r+	Open a file for reading and writing. File pointer starts at the beginning of the file.
w	Open a file for writing only. File pointer starts at the beginning of the file.
w+	Open a file for reading and writing. File pointer starts at the beginning of the file.
a	Open a file for writing only. File pointer starts at the end of the file.
a+	Open a file for reading and writing. File pointer starts at the end of the file.

fopen(argu1,argu2) function

The fopen() function is used for opening a file. It takes two arguments - file path, and file mode. For example -

$file_name = "D:/test.txt"; // file path
$file = fopen($file_name, "r");

fwrite(argu1,argu2) function

The fwrite() function is used for writing a file. It takes two arguments - first, we need to specify a file pointer and second, specify our string that we want to write. For example -

fwrite($file,"Hello world!");

fread(argu1,argu2) function

The fread() function is used for reading a file. It takes two arguments - a file pointer, and the length of the file. For example -

$size = filesize($file_name ); //return length of the file
$text = fread( $file, $size );

Note
The filesize() function returns the size of a file in bytes.

fclose(argu1) function

The fclose() function is used for closing a file. It takes one argument that holds an opened file pointer. For example -

fclose($file)

unlink(argu1,argu2) function

The unlink() function is used for deleting a file. It takes two arguments - filename, and context. For example -

unlink($file_name);

Note
The second argument, context, is an optional parameter that can be used for modifying the nature of stream or file.

File Write

After opening a file using fopen() function, the file can be written using the fwrite() function.

Example

<html>
<head>
<title>write</title>
</head>
<body>
<?php
$file_name = "D:/test.txt"; // file location path.
if(file_exists($file_name)) //file_exists() function check file does exist or not.
{
echo "File is already created....";
exit();
}
$file = fopen( $file_name, "w" ); //file opening in writing mode.
fwrite( $file, "Hello world!" ); //file wrting
fclose( $file ); // fclose() function is used for closing a file.
echo"File created successfully...";
?>
</body>
</html>

File Read

After opening a file using the fopen() function, the file can be read using the fread() function.

Example

<html>
<head>
<title>read</title>
</head>
<body>
<?php
$file_name="D:/test.txt"; // file location path.
if(!file_exists($file_name)) //file_exists() function check file does exist or not.
{
echo "File not found....";
exit();
}
$file=fopen($file_name,"r"); //file opening in reading mode.
$size=filesize($file_name);
$text=fread($file,$size); //file reading
fclose($file); //fclose() function is used for closing a file.
echo "<h3><pre>$text</pre></h3>";
?>
</body>
</html>

File Delete

After opening a file using the fopen() function, the file can be deleted using the unlink() function.

Example

<html>
<head>
<title>delete</title>
</head>
<body>
<?php
$file_name="D:/test.txt"; // file location path.
if(!file_exists($file_name)) //file_exists() function check file does exist or not.
{
echo "File not found....";
exit();
}
unlink($file_name); // file delete
echo "File deleted...";
?>
</body>
</html>

File handling is an important part of any web programming language. In this blog, I covered file read, write, and delete functions using PHP language. Thanks for reading.