This page will show a few different things you can do with files.

The rename command changes the name of an existing file. It also moves that file if you specify a different path.

rename ("existing_name.ext", "new_name.ext");

The unlink command deletes a file or list of files from the system. Be sure you want to do this. It permanently removes the files.

unlink ("filename.ext");

The chmod command controls the same chmod properties as you would do using your FTP program. It assigns or changes the chmod properties of a specified file.

chmod (mode, "filename.ext");

The mode is a zero, then the three numbers discussed on the CHMOD page.
Example :

chmod (0755, "example.txt");

In some cases, you may want to find the status of a file. These tools are sometimes referred to as the -x file tests because of the format you invoke them in. These tests are used along with a file handle to find a result.

letter...	Determines if given is...
-b	a block device
-c	a character device
-d	a directory
-e	existing
-f	an ordinary file
-g	has a setgid
-k	has a sticky bit set
-l	a symbolic link
-o	owned by a current user
-p	a named pipe
-r	readable
-s	contains any information
-t	represents a terminal
-u	has a setuid
-w	writable
-x	exectuable
-z	empty
-A	how long it has been since the given was last accessed
-B	a binary file
-C	how long it has been since a file's inode has been accessed
-M	how long it has been since the given was modified.
-O	owned by the current user. The current user's ID is set at the time of login.
-R	readable by the current user.
-S	a socket.
-T	a text file.
-W	writable by the current user
-X	executable by the current user.

Example :

# check to see if file exists if (-e "output.txt"){     print "The file actually exists! \n";     } else {     print "That file does not exist in the current directory \n";     }