close filehandle
Closes the file, socket, or pipe associated with the given
filehandle.
You don't have to close filehandle if you are immediately going to do
another open on it, since the next open will close it for
you. However, an explicit close on an input file
resets the line counter ($.), while the implicit close done by
open does not.
Closing a pipe will wait for the process executing on the pipe
to complete, and it prevents the script from exiting before the pipeline is
finished.
Closing a pipe explicitly also puts the status value of the command
executing on the pipe into
$?.
filehandle may be an expression whose value gives a real filehandle name. It may also be a reference to a filehandle object returned by some of the object-oriented I/O packages.