Recommend a book

[Peter Murray]

On Wed, 5 Jun 1996, Walter Giesbrecht wrote:
> On Wed, 5 Jun 1996, Linda Hyman wrote:
> > I suppose I should send my two cents worth to the listserv and start a
> > raging debate over PERL vs. JavaScript...
> 
>  [citations to two Perl books deleted]

The only comment that I have about the second PERL book is that a new 
version is coming out in August.  The new version of "Programming PERL" 
will cover new stuff that came in the 5.xxx version of PERL (the earlier 
book was based on version 4.036 of PERL).  The first book, "Learning 
PERL", is pretty good for both versions.  Check out O'Reilly's web site 
for more info on either book:

  http://www.ora.com/

> >  You might want to check out JavaScript though before you go to deeply into
> > yucky old PERL.  
> 
> .. stuff deleted ...
> 
> > We see the demise of PERL imminent except for special uses.

Well, if you wanted to start a debate, here it is.

I don't think PERL is going to be _replaced_ any time soon by Java.  It is
a very easy to learn, portable, and quick language to write applications. 
It is an excellent language for writing CGI scripts; there are a lot of
free modules available on the net to assist in writing CGI programs.  A 
downside to the language, though, is it is somewhat hard to read...it 
uses many symbols and short commands.  But it is a very powerful language.

With regards to Linda's comments about the debugger...I suggest she take 
a quick look through the manual page:

  http://www.perl.com/CPAN/doc/manual/html/perldebug.html

As with the rest of PERL, it is a line-by-line (not graphical) debugger, 
but is pretty complete in the features it offers...

> The problem with all of this is that *every* browser (I think) can 
> initiate the execution of a Perl script; Javascript is restricted (again, 
> I *think*) to Netscape versions 2 and up. Unless you want the bells and 
> whistles accessible to only this subset of your users, you'd better know 
> something about Perl (or C, I guess) or have only static web pages. 
> Javascript probably won't be usable by the majority of users for at least 
> 2-3 Web years (i.e., 6 months in human years).

I think there is some confusion in this.  These are the facts:

  * ANY BROWSER can ask a _server_ to run a CGI script, whether that
    script is in PERL, C, or anything else. [see note #1]

  * NETSCAPE BROWSERS (version 2.0 and higher) can execute "JavaScript"s 
    on the _client_.  The JavaScript is imbeded in the HTML of the page,
    and is run on the _client_, not the _server_.  [see note #2]

  * FUTURE BROWSERS, in general, will be able to execute Java scripts on
    the _client_ that will be able to talk to Java scripts on the
    _server_.  (Note...this is a pretty general statement.)

So, you can run CGIs in your server in nearly any language you please. 
This is usuful for database applications, shopping carts, etc...things
that need to run on the server end.  These are not the type of things
you'll run on the client end with Java or JavaScript.

(To all, please correct the facts if I got them wrong).

NOTES

 #1 As far as I know, no one has written a CGI interface for Java running
    on a server platform.

 #2 JavaScript is a subset of Java, and cannot be used to execute true
    Java scripts.  From Netscape's documentation:  "Based on the Java
    language, JavaScript extends the programmatic capabilities of Netscape
    Navigator to a wide range of authors and is easy enough for anyone who
    can compose HTML. Use JavaScript to glue HTML, inline plug-ins, and
    Java applets to each other." (from http://www.netscape.com/comprod/
    products/navigator/version_2.0/script/index.html).

    In terms of Java support in Netscape:  "Netscape Navigator 2.0
    supports Java on Sun Solaris, Sun OS, SGI IRIX, OSF/1, HP-UX, Windows
    NT, and Windows 95 platforms. Netscape anticipates shipping Java
    support for Windows 3.1, Macintosh, and AIX in the second quarter of
    1996." (from http://www.netscape.com/comprod/products/navigator/
    version_2.0/java_applets/index.html).


Peter
--
Peter Murray, Senior Systems Analyst                       pem at po.cwru.edu
Library Information Technologies         http://www.cwru.edu/home/pem.html
Case Western Reserve University, Cleveland, Ohio            W:216-368-8989