PHP File Exists
Summary: in this tutorial, you will learn how to check if a file exists in PHP using the file_exists(), is_file(), is_readable(), and is_writable() functions.
PHP provides some useful functions that allow you to check if a file exists. Let’s examine these functions and how to use them effectively.
Check if a file exists using the file_exists() function
To check if a file exists, you use the file_exist() function:
file_exists ( string $filename ) : boolCode language: PHP (php)
The file_exists() function accepts a filename and returns true if the file exists; otherwise it returns false.
The following example uses the file_exists() function to check if the file readme.txt exists in the current directory:
$filename = 'readme.txt';
if (file_exists($filename)) {
$message = "The file $filename exists";
} else {
$message = "The file $filename does not exist";
}
echo $message;
Code language: HTML, XML (xml)
If the readme.txt exists in the same directory of the script, you’ll see the following message:
The file readme.txt existsCode language: CSS (css)
…otherwise, you’ll see a different message:
The file readme.txt does not existCode language: CSS (css)
Note that the $filename can be also a path to a directory. In this case, the file_exists() function returns true if the directory exists.
Check if a file exists using the is_file() function
If you want to check if a path is a file (not a directory) and exists in the file system, you can use the is_file() function.
The is_file() function accepts a $filename and returns true if the $filename is a file and exists:
is_file ( string $filename ) : boolCode language: PHP (php)
The following example uses the is_file() function to check if the file readme.txt exists:
$filename = 'readme.txt';
if (is_file($filename)) {
$message = "The file $filename exists";
} else {
$message = "The file $filename does not exist";
}
echo $message;
Code language: HTML, XML (xml)
Check if a file exists and readable
In practice, you often want to check if a file exists before reading its contents. To check if a file exists and is readable, you use the is_readable() function:
is_readable ( string $filename ) : boolCode language: PHP (php)
The is_readable() function returns true if the $filename exists and readable, or false otherwise. Note that the $filename can be a directory.
The following example uses the is_readable() function to check if the readme.txt file exists and readable:
$filename = 'readme.txt';
if (is_readable($filename)) {
$message = "The file $filename exists";
} else {
$message = "The file $filename does not exist";
}
echo $message;
Code language: HTML, XML (xml)
Check if a file exists and writable
Before writing to a file, you need to check the file exists and is writable. In this case, you can use the is_writable() function:
is_writable ( string $filename ) : boolCode language: PHP (php)
The is_writable() function returns true if the $filename exists and writable, or false otherwise.
The following example uses the is_writable() function to check the readme.txt file exists and writable:
$filename = 'readme.txt';
if (is_writable($filename)) {
$message = "The file $filename exists";
} else {
$message = "The file $filename does not exist";
}
echo $message;
Code language: HTML, XML (xml)
Summary
- Use the
file_exists()function to check if a file exists. - Use the
is_file()function to check if a path is a regular file, not a directory, and that file exists. - Use the
is_readable()function to check if a file exists and readable. - Use the
is_writable()function to check if a file exists and writable.