Learning Unix for Mac OS X, Second Edition

Glossary

alphanumeric

Characters: letters (alpha) and numbers (numeric), including punctuation characters (such as _ and ?).

AppleTalk

A suite of transport protocols first introduced in Mac OS 7 and included in all systems since that release. One advantage of AppleTalk is that it’s very easy to add and modify devices on an AppleTalk network.

Aqua

The graphical appearance of Mac OS X.

BSD

The Berkeley Software Distribution version of Unix, BSD was the academic Unix, compared to System V, from AT&T Bell Telephone Labs, which had more of a commercial bent.

command

An instruction that you can give to a program running on the Unix system. For instance, you can type a program’s name and arguments on a command line, at a shell prompt; this command asks the shell to run that program. (The shell is a program itself; see shell.) Once a program starts running, it may accept commands of its own. For example, a text editor has commands for deleting and adding text to the file it’s editing.

The terms command and program are used almost interchangeably, probably because the program name is typed first on a command line (at a shell prompt). Shells have some built-in commands that don’t start a separate program running; one of these is cd, which changes the shell’s working directory.

cracker

A malicious person who tries to break into computer systems (usually via a network), disrupt computers and networks, steal secrets (such as passwords and credit card numbers), and exhibit other antisocial ...