PHP is the code that determines if a file exists if it is readable and if a directory exists

1. Case:

 
<?php 
$file = 'ofstack.com.php'; 
if (is_readable($file) == false) { 
die(' The file does not exist or cannot be read '); 
} else { 
echo ' There are '; 
} 
?> 

The is_readable() function determines whether the specified file name is readable.
Returns TRUE if the specified file or directory exists and is readable

2. Cases:

 
<?php 
$filename = 'ofstack.com.php'; 
if (file_exists($filename)) { 
echo "The file $filename exists"; 
} else { 
echo "The file $filename does not exist"; 
} 
?> 

file_exists -- check to see if a file or directory exists
instructions
bool file_exists ( string filename )
Returns TRUE if the file or directory specified by filename exists, otherwise returns FALSE.

3. Case:

 
<?php 
$file = 'ofstack.com.php'; 
if (is_file($file) == false) { 
die(' The file does not exist or cannot be read '); 
} else { 
echo ' There are '; 
} 
?> 

is_file -- determines whether a given file name is a normal file
instructions
bool is_file ( string filename)
Returns TRUE if the file exists and is a normal file.