posix_access

(PHP 5 >= 5.1.0, PHP 7)

Determine accessibility of a file

bool posix_access ( string $file [, int $mode = POSIX_F_OK ] )

posix_access() checks the user's permission of a file.

Parameters:

file

The name of the file to be tested.

mode

A mask consisting of one or more of POSIX_F_OK, POSIX_R_OK, POSIX_W_OK and POSIX_X_OK.

POSIX_R_OK, POSIX_W_OK and POSIX_X_OK request checking whether the file exists and has read, write and execute permissions, respectively. POSIX_F_OK just requests checking for the existence of the file.

Returns:

Returns TRUE on success or FALSE on failure.

Notes:

When safe mode is enabled, PHP checks whether the files or directories being operated upon have the same UID (owner) as the script that is being executed.

Examples:

posix_access() example

This example will check if the $file is readable and writable, otherwise will print an error message.

<?php
 
$file = 'some_file';
 
if (posix_access($file, POSIX_R_OK | POSIX_W_OK)) {
    echo 'The file is readable and writable!';
 
} else {
    $error = posix_get_last_error();
 
    echo "Error $error: " . posix_strerror($error);
}
 
?>