jacob@gore.com (Jacob Gore) (12/23/90)
/ comp.sys.next / portnoy@athena.mit.edu (Stephen L. Peters) / Dec 18, 1990 / > People talk about inaccuracies in the text, but I'd like to hear about > what others felt was really inaccurate in the book. Here is something I recently wrote up in response to a similar inquiry: Just picking the marked pages at random: P.48. He does 'cat /etc/utmp' and analyzes it. /etc/utmp is a binary file. The "$" he finds there has nothing to do with shell variables, it's part of the "time on" long integer. He'd have known that if he read the manual page for utmp. P.49, while I'm there. 'dirs' is not at all the same as 'pwd'. Again, see man pages. P.457. 'chfn' changes user's full name registration, not the password. It's for users, not just system administrators (the latter can simply change things in /etc/passwd or Netinfo or Yellow Pages, whichever is in use, but the user needs the special commands). P.480. 'hostname' does not "display the contents of the hostname variable", because there is no "hostname variable". P.523. 'who' and 'whoami' are not versions of the same command. P.182. 'lpr' command works on Postscript, not only on text. Depending on the setup, it can work on many other formats, TeX and troff output are commonly done. P.183. "Nobody's ever figured out a reason for 300 dpi (other than saving printer toner, maybe)". The reason for 300 dpi is to print images that scale to 300 dpi better than to 400 (for example, pictures scanned at 300 dpi, or bitmap fonts generated for 300 dpi printers). P.123. "The Change Disk Name is ONLY used for optical disks. Hard disks, because of UNIX conventions, don't have names." Disk name has nothing to do with optical or hard disks, or with root directories. Every disk on the NeXT has a name, and every disk has at least one root directory (one per partition). Only one partition can be mounted so that its root directory is the root directory of the whole file system ("/"). The rest are mounted as subdirectories of any partition that is already mounted. P.57. "Another UNIX daemon is 'lpr', for Line PRinter". 'lpd' is the daemon; 'lpr' is a client of 'lpd'. P.50. "Other commands must have arguments. If you omit a needed argument, the shell will prompt you." The shell in Unix has no way of knowing what arguments a command needs. Very few unix commands prompt users for missing arguments. P.16. "cat | sort somewords" kind of works, by coincidence. The proper command is "cat somewords | sort" or, better, "sort < somewords" or, in the case of 'sort', just "sort somewords". P.523. 'wall' writes to all users on the machine, not on the network. P.300. "Other views that you create in windows are subclasses of contentView." They are SUBVIEWS of contentview. P.285. "if [myCell isHighlighted]" is not valid Objective-C syntax. P.224. UUCP commands have nothing to do with Internet. They can be made to work over IP, but that requires administrator interference on both ends of the link. -. "." and "@" are NOT interchangable in internet addresses. -. "68xxx" is not a valid subdomain. There are many more. > I can't read the > review referenced in one of the Buzzings, because I don't have a NeXT > (yet). Sorry, I should have thought of that. I'll submit a Postscript version to the archives. > On another note, does anyone know of _good_ descriptions of the > Objective-C language. Hard to say... Brad Cox's "Object-Oriented Programming: An Evolutionary Approach" is pretty good, but it describes an earlier version of Objective-C than the one used on the NeXT. An updated edition of that book is in the works, but I don't know when it'll be available. In the meantime, the documentation NeXT ships may suffice for you, or you could try ordering Stepstone's latest manuals (I haven't seen them). Jacob -- Jacob Gore Jacob@Gore.Com boulder!gore!jacob