PHP working with Files and Directory

Below are some of the important methods used when working or manipulating the files or folders

parse_ini_file($filename)
parse_ini_file() loads in the ini file specified in filename, and returns the settings in it in an associative array.
Example
// Parse without sections
$ini_array = parse_ini_file("sample.ini");
print_r($ini_array);

// Parse with sections
$ini_array = parse_ini_file("sample.ini", true);
print_r($ini_array);
O/P
Array
(
[one] => 1
[five] => 5
[animal] => Dodo bird
[path] => /usr/local/bin
[URL] => http://www.example.com/~username
[phpversion] => Array
(
[0] => 5.0
[1] => 5.1
[2] => 5.2
[3] => 5.3
)

)
Array
(
[first_section] => Array
(
[one] => 1
[five] => 5
[animal] => Dodo bird
)

[second_section] => Array
(
[path] => /usr/local/bin
[URL] => http://www.example.com/~username
)
)

basename($path)
Given a string containing a path to a file, this function will return the base name of the file.
Example
$path = "/home/httpd/html/index.php";
$file = basename($path); // $file is set to "index.php"

dirname($path)
Given a string containing a path to a file, this function will return the name of the directory.
example
$path = "/etc/passwd";
$file = dirname($path); // $file is set to "/etc"

pathinfo($_SERVER['PHP_SELF'])
pathinfo() returns an associative array containing information about path.
Example
$path_parts = pathinfo('/www/htdocs/inc/lib.inc.php');

echo $path_parts['dirname'], "\n"; //www/htdocs/inc
echo $path_parts['basename'], "\n"; //lib.inc.php
echo $path_parts['extension'], "\n"; //php
echo $path_parts['filename'], "\n"; // lib.inc

realpath($path)
realpath() expands all symbolic links and resolves references to '/./', '/../' and extra '/' characters in the input path and return the canonicalized absolute pathname
Example
echo realpath('/windows/system32'); //C:\WINDOWS\System32

getcwd()
Gets the current working directory.

file_exists
hecks whether a file or directory exists