Re: [MacPerl] Code cleaning and questions

[Robert Pollard <robpoll1@bellsouth.net>]

Thanks for the reassurance and encouragement.  I knew there was a positive group
of MacPerlers out there somewhere.

Thanks to the tremendous amount of information and encouragement.  Even though he
had some "additional advice", thanks to Ronald for helping as well.

I am studying the ".t" examples.  This is really where I want to be eventually.  I
envy Kevin Reid.  He has the knowledge I am on a crusade to aquire.  So what I am
doing is writing basic level programs and studying in parallel on the toolbox.  I
have a mission.  It is to install a Unix version of Perl on my Sun servers, write
database access routines to access Oracle and then be able to use a custom MacPerl
application to read the Oracle data via Proxy.

I'll be back for sure.

Thanks a lot for everything.

Robert Pollard

cetasix@pop.erols.com wrote:

> Robert,
>
> Concerning Ronald, what an ego! I too am learning and I do not appreciate
> an ego maniac bashing me for not knowing what he did. For him to be so
> unpleasant suggests that he is not very happy with himself or he is a world
> class jerk. I like how you dealt with him. Very diplomatically.
>
> Anyways, I like your question/issue and it helped me as well. I think
> you'll be a good programmer if you stick it in there. Anyways, keep
> plugging away.
>
> alan :)
>
> >Ronald J Kimball wrote:
> >
> >> On Thu, Jun 24, 1999 at 09:48:04AM -0500, Robert Pollard wrote:
> >> > Hello everyone,
> >> >
> >> > I have a snippet of code I would like to ask questions about.  I am a
> >> > newbie so I won't even raise your brainwave level far above a coma.
> >> > I did this little bit of code to check the contents of a file for any
> >> > strange characters.  The file was causing a freeze and I thought there
> >> > may be something odd in it.  It turned out there wasn't but I have some
> >> > questions about it.
> >> >
> >> > open(SOURCE, '<Robert:Desktop Folder:Addresses') or die;
> >> > open(DEST, '>Robert:Desktop Folder:Addresses.clean') or die;
> >> > 1)   Does the open command always read the whole file in.
> >>
> >> The open() function does not read any of the file in.  It just creates a
> >> filehandle that you can use to read the file in later.  (Or write to, or
> >> whatever, as appropriate.)
> >>
> >> > This is an
> >> > interesting syntax because what this did was to put the whole contents
> >> > of a file line by line into an array.  What if my text were very long
> >> > paragraphs and exceeded the maximum character limit of the variable for
> >> > each element?
> >> >    @line = <SOURCE>;
> >>
> >> I'm not sure what would happen if you had a line that was longer than the
> >> maximum character limit.  I believe that limit is somewhere between 255
> >> megabytes and 4095 megabytes for a single scalar value, at least on the
> >
> >This is very good
> >
> >>
> >> system I did a bit of testing on just now - at the upper end, the scalar
> >> came back empty.  Anyway, it's more likely MacPerl will run out of memory
> >> before you manage to fill up a scalar variable.
> >>
> >> > 2)  Why do I need to chomp.  The program ran fine and put everything
> >> > aout like it was suppose to.  I believe this is for stripping the CRs at
> >> > the end of the line?
> >> >    #chomp($line);
> >>
> >> Yes, that is what it is for.  If you're not _sure_ what chomp() does, why
> >> didn't you read the documentation???
> >
> >Because I couldn't get to the documentation to double check what I thought I
> >had read.  I have the book on order for over 2 weeks with no indicator of when
> >I will see it and the online version wasn't available.  I believe the server
> >was down.  I checked this morning and it still wasn't available.  I apologize
> >for not being able to remember things that I glance at, but there is so much
> >to take in.
> >
> >>
> >>
> >> If you don't want to remove the newlines, you don't need to chomp().
> >>
> >> > print "@line\n";
> >>
> >> Are you sure this is what you want to do?  This prints with a space between
> >> each array element, and adds an extra newline at the end.  You probably
> >> meant:
> >> print @line;
> >>
> >> Read the documentation on quote operators and the $" variable.
> >>
> >> > foreach $line (@line) {
> >> >    ($Name, $Phone, $Address, $Type) = split(/\t/, $line);  # This cool.
> >> > I would use this before I would allow the split to assign each line
> >> > # to different elements in the array.  In the importation of records,
> >> > this seems to be the best way to write to arrays in row/column fashion.
> >> >
> >> > 3)   Here I didn't have to use the angle brackets around the
> >> > filehandle.  If I did it seemed to refer to the whole file.  Without
> >> > them, it allows whatever you want to put out.  As in this case I was
> >> > able to put out a whole line at a time.
> >> >    print DEST $line;
> >>
> >> Angle brackets around a filehandle are the _input_ operator.  If you're
> >> trying to output to a filehandle, you should not use the input operator on
> >> it.  Once again, why haven't you read the documentation???
> >
> >I'm sorry but this tidbit didn't jump out at me when I went over the
> >documentation.  I went back and looked for it under "Builtin functions" under
> >"open" and still didn't see this.  Maybe they assume you can figure it out.
> >
> >>
> >>
> >> >    print("The name is $Name.\n");
> >> > # This is where I convert each character to the ascii representation.
> >> >    print("The ascii representation is:\n");
> >> >    for ($i=1;$i <= length($line);$i++) {
> >> >       $num = ord(substr($line, $i, 1));
> >> >       print("$num,");
> >> >       if ($num > 127) {
> >> >         print ("\n\nW A R N I N I N G -- ASCII value exceeds 127\n\n");
> >> >       }
> >> >    }
> >> >    print("\n");
> >> > }
> >> > close(SOURCE);
> >> > close(DEST);
> >> > 4)   Could you guys give me any tips/hints on code optimization?
> >> >
> >>
> >> Tip #1.  Read the documentation.
> >
> >I have and am continuing to.  You may be one of those genius types that can do
> >things like look at hexadecimal code and know exactly what it does.  Me, it
> >takes time.
> >
> >>
> >>
> >> Tip #2.  Try to program in Perl, not in C.  The for loop above is how you
> >> would solve this problem in C.  A more Perlish way would be:
> >>
> >> foreach (split //, $line) {
> >>   print $num = ord $_;
> >
> >I have looked for "$_" throughout the documentation in both the MacPerl: Power
> >and Ease and in the documentation.  I can't find it anywhere.  I wish I could
> >do a keyword search but I can't and it takes time to find these things.
> >
> >Thanks for the Perlish way of doing this.  I am having a hard time adjusting
> >to Perl.  This is what I was hoping someone would show me.  I hope you
> >remember in the first part of this request I said I was a newbie.  If I had as
> >much time in Perl development as you I would understand your frustration in my
> >basic level questions.  Everybody has to start somewhere.  I have been
> >programming in 4th Dimension, SQL and a little C for so long, Perl is really
> >strange to me.
> >I can only offer you 2 options: 1) Please be patient with me or 2) if I annoy
> >you then don't respond to any of my requests.
> >
> >Still and yet, thank you for taking the time.
> >
> >Robert Pollard
> >
> >>
> >>   $num > 127 and warn "WARNING -- ASCII value exceeds 127.\n";
> >> }
> >>
> >> Ronald
> >
> >
> >===== Want to unsubscribe from this list?
> >===== Send mail with body "unsubscribe" to macperl-request@macperl.org


===== Want to unsubscribe from this list?
===== Send mail with body "unsubscribe" to macperl-request@macperl.org