The PHP glob() function returns an array of filenames or directories matching a specified pattern.

The PHP is_dir() function checks whether the specified filename is a directory.

The PHP is_executable() function checks whether the specified filename is executable.

The PHP is_file() function checks whether the specified filename is a regular file.

The PHP is_link() function checks whether the specified filename is a symbolic link.

The PHP is_readable() function checks whether the specified filename is readable.

The PHP is_uploaded_file() function checks whether the specified file is uploaded via HTTP POST.

The PHP is_writable() function checks whether the specified filename is writable.

The PHP lchgrp() function changes the group ownership of a symbolic link (a link in the filesystem).

The PHP lchown() function changes the user ownership of a symbolic link (a link in the filesystem).

The PHP link() function creates a hard link.

The PHP linkinfo() function returns information about a hard link, and is used to verify if a link really exists.

The PHP lstat() function returns information about a file or symbolic link.

The PHP mkdir() function creates a directory specified by a pathname.

The PHP parse_ini_file() function parses a configuration (ini) file and returns the settings.

The PHP pathinfo() function returns information about a file path.

The PHP pclose() function closes a pipe opened by popen().

The PHP popen() function opens a pipe to the program specified in the command parameter.

The PHP readfile() function reads a file and writes it to the output buffer.

The PHP readlink() function returns the target of a symbolic link.