Errata / Updates
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1999-11-09 05:37


Errata and Updates: notes on and amendments to the Weekly Exercises and Readings

Here are corrections to the weekly readings and to the text books for this course:

Weekly Exercises: corrections and helpful hints

Using islib on ACADAIX

Some of Maitang's assignments and questions require you to fetch files from the islib (Information Systems Library) directory (e.g. question 3-28).  On ACADAIX Unix you can use the islib command (actually, a defined function) from your login Korn shell to do this.  Simply type islib at the shell prompt and follow the menu instructions.  (The islib command only works from your login shell, since it is actually a function defined at login time.)

4-3: See "Including the Current Directory in the Korn Shell Prompt" in Chapter 5.
4-16: Reword as: Explain how to remove completely a file that is linked into several directories and/or that has several names that are links.
5-*: "Core Program" means "the Unix Kernel" (text p.303).
5-5: There are only five places, since you may consider "&&" and "||" to be the same type of operator.
5-15: $0 stands for the name of the script being executed.

Unix Textbook: corrections and helpful hints

Chapter 5 (top of p.326):
To redirect both stderr and stdout to the same file using the Korne or Bourne shells:
    ls -l enlightenment /etc/passwd >err+out 2>&1
Read this as: First redirect stdout (unit 1) into err+out, then redirect stderr (unit 2) to the same place as stdout (unit 1).
Chapter 5 (p.330): Curly braces { and } don't work in the ACADAIX version of the Korn shell; they have no special meaning there.  They do work in the Linux version of ksh, and they also work in the C shell csh (where they originated).  (The C Shell is available on ACADAIX.)
Chapter 5 (p.344): Ignore the entire section "Mixing Shell Variables with Other Text on the Command Line".  Most of it is either wrong or misleading.  If you want to put text up against the right side of a variable, enclose the name of the variable in curly braces using this syntax:   ${variable}text
Chapter 5 (p.360): The ACADAIX Korn shell doesn't understand vi-tabcomplete.
Chapter 5 (p.371):
Ignore what it says about "// Turns off and on interpretation of most special characters".  It's nonsense.
Note that "?" also does not match a leading dot in a file name.
The braces { and } don't work on ACADAIX.
Chapter 8 (p.469): Where they wrote "On BSD" they should have written "using the C shell".  Where they wrote "On System V" they should have written "Using the Korn or Bourne shells".

Web Author: Ian! D. Allen
Updated: 1999-11-09 05:37