Using the Internet

Using the Internet

The tools described here are the main programs you will use to interact with other machines over the Internet. Although, technically speaking, anything you do over the Internet involves interacting with another machine, these tools are the ones you will use more intensively for command-line work.

telnet

telnet is a command for connecting to another machine. Use it to log in to the other machine and get a shell prompt from it, just as the Terminal application gives you a shell prompt on your machine.

telnet is mostly deprecated these days because it sends data and passwords without encryption, and does not provide the kind of secure connections that ssh provides. See Chapter 12, "Security," and man telnet for more details.

ssh

ssh ( Secure Shell ) is a tool for creating encrypted connections to other machines over the Internet. Like telnet , ssh can be used to log in to another machine. It can also be used to create secure connections between machines for file transfer (see the " scp " section below), or to relay incoming data to a different machine for handling, among other capabilities.

ssh is the preferred tool for connecting to other machines through the Internet. The basic command line to log in to another machine is

ssh [e-mail]

See Chapter 12 and man ssh for details.

scp

scp ( Secure Copy ) is a tool for transferring files between machines on a network. scp uses ssh to provide an encrypted connection. See Chapter 12 and man scp for details.

ftp and sftp

ftp ( File Transfer Protocol ) is an old tool for transferring files between machines on the Internet. It provides a way of logging in to an FTP server and interactively exchanging files. Because the FTP protocol sends passwords and data without encryption, it shares the vulnerabilities of telnet and is less desirable than scp or a new alternative, sftp ( Secure ftp ). See Chapter 12, man ftp , and man sftp for details.

Lynx

Lynx is a command-line, text-only Web browser.

Mac OS X doesn't come with Lynx ; see Chapter 15 to learn how to install it. (See also the curl and wget commands, covered in Chapter 10.)