change.log

Shall高级编程

10) In "Internal Variables" section of "Variables Revisited" chapter:
    Fixed up comments in "t-out.sh" example to reflect changes
    in Bash 3.x.
    (Thank you, Frank Wang.)
    Fixed up explanation of "anomalous" output given by ${PIPESTATUS[@]}
    in certain situations.
    (Thank you, Frank Wang, for providing Chet Ramey's explanation.)

11) In "Typing Variables" section of "Variables Revisited" chapter:
    Added caution + example of how "typeset" restricts the scope of a
    variable.
    (Thank you, Michael Iatrou.)


12) In "File and Archiving Commands" section of "External Commands" Chapter:
    At "file" entry, fixed typo (/usrlocal/bin => /usr/local/bin).
    Fixed error in "strip-comments.sh" example script.
    (Thank you, Jesse Gough.)

13) In "Complex Commands" section of "External Commands" Chapter:   
    At "xargs" entry, added extra usage example.
    At "expr" entry, added example of illegal arithmetic operation.

14) In "$RANDOM" section of "Variables Revisited" chapter:
    Added Frank Wang's alternative to jipe's example.

15) In "Quoting" chapter:
    Split the chapter into introduction and "Quoting Variables" and
   "Escaping" sections.

    Corrected note about unquoted "grep" . . .
    Added discussion about quoting correcting echo's appetite for newlines.
    Clarified explanation of referencing quoted variables
    and added footnote.
    Amended tip about double quotes being necessary only to prevent word
    splitting.
    (Thank you, Harald Koenig.)

16) In "Local Variables" section of "Functions" chapter:
    In footnoted example of a segfaulting recursive function,
    added an "echo" to properly exercise the function.
    (Thank you, Dr. Roland Sonnenschein.)

17) In "Debugging" chapter:
    At listing of "Tools for debugging non-working scripts,"
    added list item for "$LINENO" variable and "caller" builtin.

    At "trap" entry, replaced buggy "multiple-processes.sh" example.
    (Thank you, Tedman Eng.)

18) In "Copyright" appendix:
    Updated licensing terms to give the LDP the right to reassign custodianship
    of the book in the event the author cannot be contacted.

19) In "Bibliography" section:
    Added entry for Peter Knowles' booklistgen.sh --
    Sony Librie booklist generator -- making possible
    Linux access to this neat e-book reader.

20) Corrected spelling of the name of contributor St閜hane Chazelas
    in multiple places.
    (Thank you, Bertrand Mollinier Toublet, for pointing out these
    embarrassing typos.)

21) Various changes and fixups in example scripts.



Version 3.5
Boxberry release, 06/05/05



1) In "Indirect References to Variables" section of "Variables Revisited" chapter:
   Added "ugly kludge" sidebar.

2) In "Variable Assignment" section of "Introduction to Variables and
   Parameters" chapter:
     After "ex16.sh" example, noted that $(...) construct is a form of
     command substitution.

3) In "Special Variable Types" section of "Introduction to Variables and
   Parameters" chapter:
     In note about remedies for missing command-line parameters,
     added discussion about using parameter substitution,
     rather than adding extra characters to variable names.
     (Thank you, Fabian Kreutz.)

4) In "Command Substitution" chapter:
   At note at end of chapter, added mention that nesting is possible
   with $(...) construct, and added "agram2.sh" example script.

5) In "Internal Commands and Builtins" chapter:
   At "exec" entry, added footnote and streamlined text.

6) In "File and Archiving Commands" section of "External Commands" Chapter:
   At "more/less" entry, added "testing command sequence" usage example.
   At "mktemp" entry, added usage example and elaborated existing example.

7) In "Communications Commands" section of "External Commands" chapter:
   At "dig" entry, added "spam-lookup.sh" example.

8) In "Text Processing" section of "External Commands" Chapter:   
   At "tail" entry, added usage example of combining "head" and "tail"
   to extract a specific line or lines from a text file.

9) In "System and Administrative Commands" chapter:
   At "umask" entry, added "rot13a.sh" example script.

10) In "Complex Functions and Function Complexities" section of "Functions"
chapter:
    Added in-line example ("days in month") of capturing function "echo"
    as "return value."

11) In the "Shell Wrappers" section of "Miscellany" chapter:
    Added "pr-asc.sh" example script.

12) Changed "Files" chapter into an appendix.

13) In the "Sed and Awk Micro-primer" appendix:
    More examples of the awk "print" command.

14) In "Contributed Scripts" appendix:
    Added "whx.sh" script.
    (Thank you, Walter Dnes.)

15) Miscellaneous fixups and stylistic changes in the text and various
    scripts.
    Fixed up three misspellings of "permissible"!
    Updated morethan.org site address.



Version 3.4
Teaberry release, 05/08/05

1) In "Special Characters" chapter:
   Some minor additions and cleanups.

2) In "Basic Commands" section of "External Commands" Chapter:   
   At "ls" entry, minor fixups on "ex40.sh" example.
   At "rm" entry, added "rm -- -badname" method of deleting hyphen-prefixed
   filenames.

3) In "Time/Date Commands" section of "External Commands" chapter:
   At "date" entry:
     Added mention of "TZ=XXX" option.
     (Thanks, Frank Kannemann and Pete Sj鯾erg.)
     Also added discussion of additional options.

4) In "Communications Commands" section of "External Commands" chapter:
   At "lynx" entry, added paragraph on "-traversal" option.
   At "wget" entry, added comments to "quote-fetch.sh" example script.

5) In "Miscellaneous Commands" section of "External Commands" Chapter:
   At "sox" entry, added links for examples of script use.
   At "getopt" entry, fixed typo.

6) In "Math Commands" section of "External Commands" chapter:
   At "dc" entry, added echoing obfuscated text entry.

7) In "Internal Commands and Builtins" chapter:
   At "echo" entry, added comments to in-line examples of
   embedding linefeed in a string.
   (Per suggestion of Michal Jaegermann.)
   At "hash" entry, added footnote explaining what a hash is.
   Modified "col-totaler3.sh" example script to make it more interesting.
   At "forking" sidebar, added paragraph about parent-child process problem.

8) In "File test Operators" section of "Tests" chapter:
   Added deprecated "-a" option.

9) In "System and Administrative Commands" chapter:

   Added "nc" entry, and
     Added "iscan.sh" example script.
     (Thank you, Hobbit.)

     Added Dr. Andrew Tridgell's famous one-line script.
     (Thank you for permission to quote it, Tridge.)

   At "logrotate" entry, added URL for Stefano Falsetto's "rottlog"
   project.
   At "ps" entry, added graphical "tree" options. 

   Added "quota" entry.

   Separated "Analyzing a System Script" into a section of its own.


10) In "Bash, version 3" section of "Bash, versions 2 and 3" chapter
    At "=~" entry, added Social Security number example.
    Added end of chapter note that version 3 update breaks a few old
    scripts.


11) In "Testing and Branching" section of "Loops and Branches" chapter:
    Added code snippet from Stefano Falsetto's "rottlog" package.
    (Thank you, Stefano.)

12) In "Debugging" chapter:
    Added Stefano Falsetto's "debecho ()" debugging echo.
    (Thank you, Stefano.)

13) In "$RANDOM" section of "Variables Revisited" chapter:
    Added footnote discussing "seeds."

14) In "Parameter Substitution" section of "Variables Revisited" chapter:
    Changed "rfe.sh" example to use "case" construct to test for
    command-line parameters.

15) In "Manipulating Strings" section of "Variables Revisited" chapter:
    Added "getopt-simple.sh" example.
    (Thank you, Chris Morgan.)

16) In "Gotchas" chapter:
    Added comments about 'exporting' inner shell variables to
   "subshell-pitfalls.sh" example.
    Added note that, as of Bash 3,  periods are no longer permitted
    within variable or function names.


17) In "Here Documents" chapter:
    Added Huxley epigraph.
    Reshuffled order of first several examples.
    Added in-line example of an "ex script" (Smith/Jones replacement).

18) In "Regular Expressions" chapter:
      In "Globbing" Section:
        Stylistic fixups. Added footnote.

19) In "Assorted Tips" section of "Miscellany" chapter:
   Corrected "dialog.sh" example.
   Added entry on setting a variable to the contents of a sed or awk script,
   with cross-references to a couple of example scripts.

20) In "Contributed Scripts" appendix:
    Added Mariusz Gniazdowski's "Hash.lib" hashing library for scripting,
    and an example script using the library ("hash-example.sh").
    (Thank you, Mariusz.)
    Minor revision of "mail-format.sh" example (converted sed script to a
    variable)

21) In "Writing Scripts" section of "Exercises" appendix:
    Added "Removing Inactive Accounts" exercise to "Intermediate" section.
    Added "Checking for Broken Links" exercise to "Intermediate" section.

22) In "Bibliography" section:
    Added Henry Spencer epigraph.
    Added "Wicked Cool Shell Scripts" entry.
    Added "seder's grabbag."
    Added Linuxreviews.

23) Miscellaneous stylistic changes in various scripts.

24) Many minor stylistic changes in the body of the text.



Version 3.3
Raspberry release, 03/20/05

1) In the "Starting Off With a Sha-Bang" chapter:
   Amended footnote [3] to mention a cat / here document.
   (Thank you, Fabian Kreutz.)
   Fixed typo in "ex1a.sh" example.
   (Thank you, Preetam.)
   Added Larry Wall epigraph.
   Changed "Important" block to "Tip," and added "generalizing scripts"
   paragraph.

2) In "Special Characters" chapter:
   At "#" entry, noted that if comment follows a command on a line,
   then whitespace preceding the "#" is necessary.
   (Thanks, Le Wen.)

3) In "Basic Commands" section of "External Commands" Chapter:   
   Greatly expanded discussion of "chattr" entry.

4) In "File and Archiving Commands" section of "External Commands" Chapter:
   Added "rpm -qf" tip at "rpm" entry.

5) In "Text Processing" section of "External Commands" Chapter:   
   Added "enscript" entry.
   At "egrep" and "fgrep" entries.
     added symbolic link note
     added "dict-lookup.sh" example script.
   Updated "wc" entry.

6) In "Communications Commands" section of "External Commands" chapter:
   Added "netconfig" entry.

7) In "Math Commands" section of "External Commands" chapter:
   Fixup of "hexconvert.sh" example script
   (had left out initialization of E_NOARGS variable)
   (Thanks, Stefano Palmeri.)

8) In "Internal Commands and Builtins" chapter:
   At "forking/spawning" sidebar:
   Added "spawn.sh" example

9) In "Job Control Commands" section of "Internal Commands and Builtins"
   chapter:
   Corrected note discussing zombie processes.
   (Thank you, Alan Sundell.)

10) In "Here Documents" chapter:
    Removed reference to 'telnet' -- since it's generally not a good idea.

11) In "Of Zeroes and Nulls" chapter
    Added/revised discussion of /dev/zero.

12) In the "Shell Wrappers" section of "Miscellany" chapter:
    Added footnote giving examples of system utilities that are really
    shell wrappers.
    Added "logging-wrapper.sh" example.

13) In "Indirect References to Variables" section of "Variables Revisited" chapter:
    Expanded Nils Radtke's example of building dynamic variable names.

14) In "Parameter Substitution" section of "Variables Revisited" chapter:
    Fixed up "ex6.sh" example to make it less ambiguous,
    per suggestion of "Der Schwadde" . . . ).

15) In "Miscellaneous Commands" section of "External Commands" Chapter:
    At "dd" entry," added lowercase conversion in-line example.
    At "jot/seq" entry, added "letter-count.sh" example script.
    (Thanks, Stefano Palmeri.)

16) In "System and Administrative Commands" chapter:
    At "lockfile" entry, fixed typo in inline example.
    (Thanks, Andreas Abraham.)
    At "fuser" entry, added more material.

17) In "Gotchas" chapter:
    At "Mixing up '=' and '-eq' entry, fixed typo.
    (Thanks, Andreas Abraham.)

18) In "Colorizing Scripts" section of "Miscellany" chapter:
    Added "horserace.sh" example.
   (Thanks, Stefano Palmeri.)

19) In "Redirecting Code Blocks" section of "I/O Redirection" chapter:
    Added code snippet and commentary to redir2.sh example.
    (Thank you, Bruno de Oliveira Schneider.)

20) In "Copyright" appendix:
    Added second URL for French translation.

21) In the "Sed and Awk Micro-primer" appendix:
    Fixed "letter-count.sh" example to work with gawk, ver. 3.1.3.
    (Thanks to Stefano Palmeri for pointing out the need for a fixup.)
    Renamed filename to "letter-count2.sh" to accommodate alternate
    version of script which will appear prior to this one in the text.

22) In "Contributed Scripts" appendix:
    Fixups to "wgetter2.bash" script.
    Added "bashpodder.sh" script.
    (Thank you, Linc Fessenden.)

23) In "Writing Scripts" section of "Exercises" appendix:
    In "Intermediate sub-section":
      Added "Enforcing Disk Quotas" exercise.

24) Various miscellaneous fixups and enhancements:
      In example scripts.
      In citations of book titles (inserted <citetitle> tag).