Filehandles are the foundation of networked applications. In this section we review the ins and outs of filehandles. Even if you're an experienced Perl programmer, you might want to scan this section to refresh your memory on some of the more obscure aspects of Perl I/O.
A filehandle connects a Perl script to the outside world. Reading from a filehandle brings in outside data, and writing to one exports data. Depending on how it was created, a filehandle may be connected to a disk file, to a hardware device such as a serial port, to a local process such as a command-line window in a windowing system, or to a remote process such as a network server. It's also possible for a filehandle to be connected to a "bit ...