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Re^11: incrementing already existing file

by broomduster (Priest)
on Mar 03, 2011 at 13:50 UTC ( #891222=note: print w/replies, xml ) Need Help??

in reply to Re^10: incrementing already existing file
in thread incrementing already existing file

In this section of your code:
while ( <MYFILE> ) { chomp; my( $label, $index, $value ) = ( split /\s+/ )[3, 5, -1]; $a_vals[ $index ] = $value; $b_vals[ $index ] = $value; }
You need to check the value of $index to get the values for type 'A' into @a_vals, similarly for the 'B' values. The way you have it, you only get 'B' values because they are the last ones in MYFILE, and you are putting the same things into both @a_vals and @b_vals. Since the 'B' values come in last, they overwrite the corresponding 'A' values in @a_vals. You can use the same kind of if/elsif/else logic as in your other loop to fix this(but see comments below on ways to improve that).

Now for this part of the loop over NEWF:

if ($label eq "A"){ $fields[-2] = $a_vals[ $index ] } if ($label eq "B"){ $fields[-2] = $b_vals[ $index ]

You should use if / elsif / else here:

if ($label eq "A") { $fields[-2] = $a_vals[ $index ] } elsif ($label eq "B") { $fields[-2] = $b_vals[ $index ] } else { print "OOPS! bad label\n"; # complain if something is fishy }

You're getting there.

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Re^12: incrementing already existing file
by wanttoprogram (Novice) on Mar 03, 2011 at 16:50 UTC
    Perfect. It worked. Thank you for your clean answers and time.
      My pleasure. I'll offer one other piece of advice. roboticus already said pretty much the same thing here, but it bears repeating. Get into the habit of keeping nested blocks of code properly indented; each new block should be indented more than the block that contains it. When you see that you have levels of indentation (i.e., many levels of nesting), it's usually a clue that you need to think again about what you are doing. As you get more experience, this will become automatic, but you can always use a program called perltidy to help you keep things neat.

      Keep at it. You will get the hang of it. I just takes practice.

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[ambrus]: If you don't do that, some people will be able to use only two thirds of the available screen area, or have to prepare three versions of their slides, each of which is a waste that you could avoid with one simple phrase in the call for papers.
[Corion]: As for somebody hosting national conferences, we don't always know the kind of connectors and aspect ratios available ;)
[ambrus]: Corion: well sure, but that's the similar to any printed document, and the margin is diminishing with today's technology. Video games no longer have to assume that the CRTs won't show the edges of the screen.
[Corion]: If you cram your slides with that much information, they might work in an "offline" situation but not very well for a live presentation IMO
[ambrus]: Corion: in that case I also ask the people who rent the conference rooms to tell conference organizers about the available tech.
[Corion]: ambrus: No, you're misunderstanding. If you place content too far on the left/right/top/ bottom, people might not see it because the view is obstructed ;)(
[Corion]: In Amsterdam, the screen went down to the bottom of the stage (60cm above ground) and the seating was on the ground, meaning that the rows in the back couldn't see the bottom of slides.
[Corion]: There also were some columns that meant that maybe you couldn't see the left/right edge of a slide.
[ambrus]: Corion: Sure. I've had a course in a 50 seat lecture hall that has two fucking columns in the middle.
[Corion]: Talking about it, the top should be fairly visible in the situations I've experienced at least. The top is uncomfortable for people in the first three rows, but that's life ;)

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