The measure of a computer language command reference is its ability to balance depth and breadth with clarity and accessibility. A language reference is no different from a database except for the constraint that a human being will access the database with two hands, furrowed brows, and a sense of urgency.
Patrick Volkerding and Kevin Reichard have struck a workable balance in Linux System Commands, a reference that provides brief descriptions and commonly used command-line options for end users. The entries are not intended to be exhaustive, and more information on any command can be obtained by using the online man pages. The command list is, likewise, limited to commands that end users will need, according to the authors' opinion. System administrators who need rapid access to descriptions of more sophisticated commands, such as routed, will have to seek other references, such as Scott Hawkins's fine Linux Desk Reference.
Part I, which comprises 50 pages, is highlighted by two tables that map common end-user needs onto the appropriate Linux command. The first table correlates a routine task with its Linux command, and the second table correlates MS-DOS commands with their Linux equivalents. The first contains many relatively obscure Linux commands that deserve browsing. For instance, rev reverses character order on each line of a file--an uncommon need, but useful in context.
Part II, the main commands reference, is divided into seven topical areas: general (including X11), file management, text processing, Internet/e-mail, programming, networking, and MS-DOS tools. Each chapter is composed of alphabetized, one-page synopses of the major commands. For brevity, examples of command use are omitted from the synopses.
Part III, which covers Linux shells, is so brief as to be inconsequential.
Commands references are not without their allegiances. Volkerding, who maintains the Slackware distribution of Linux, includes a description of installpkg, the Slackware package installer, but omits rpm, the rival Red Hat package manager, from his list. Betraying sympathies for Macintosh, Volkerding and Reichard emphasize Linux commands that control HFS, the Macintosh file system.
Linux System Commands should be left in a place where you are likely to browse it peacefully on a daily basis, if only for 5 or 10 minutes at a time. It also would do well next to your computer. --Peter Leopold