[kelesh]

I have a script that outputs a list of text(usernames), and I want to make it into a pretty 3xN grid(3 columns 10 characters wide each, and as many rows as it takes). How can I do this in perl? I am learning perl but I don't know nearly enough to do this yet.

script1 outputs a list of names, 1 on each line. this would be script2.

i want:
script1 | script2 to output the list in with names in 3 columns, with some centering. For a good description of the problem, with an example and method: http://web.mit.edu/kelesh/Public/formatting-script

I wrote the step-by-step method down there, I just need to put it into perl code and it will work.

[Paul McCann]

Err, nup to the l337 claim, but maybe this will get you started toward what you're after. If you save it as, say, "table.pl" in your ~/bin directory, and "chmod u+x ~/bin/table.pl", then "rehash", you should be able to just pipe
your list of names to it (as required).

Cheers,
Paul

Code:
#!/usr/bin/perl -w
use strict;
while(<>){
chomp;
my $l=length(); # number of characters in the username
my $pre=int(5-($l+1)/2); # amount of "pre" space
print " "x$pre.$_." "x(10-$pre-$l);
print "\n" unless ($.%3);
}

[Wevah]

Originally posted by Paul McCann:
Err, nup to the l337 claim, but maybe this will get you started toward what you're after. If you save it as, say, "table.pl" in your ~/bin directory, and "chmod u+x ~/bin/table.pl", then "rehash", you should be able to just pipe
your list of names to it (as required).

Cheers,
Paul

Code:
#!/usr/bin/perl -w
use strict;
while(<>){
chomp;
my $l=length(); # number of characters in the username
my $pre=int(5-($l+1)/2); # amount of "pre" space
print " "x$pre.$_." "x(10-$pre-$l);
print "\n" unless ($.%3);
}

You could just use

Code:
printf "%-10s%-10s%-10s\n",$foo,$bar,$baz;

for one row, and not have to do all that length calculation...

[kelesh]

wevah, i'm not sure i understand that code but it probably works.

paul, thanks alot man, you're 1337 in my book

i got ahold of "learn perl" by oreilly. this stuff looks awesome.

[Wevah]

Check a Perl reference for printf. It prints out formatted strings, so you can use it to avoid having to calculate the length of your strings.

[Paul McCann]

Originally posted by Wevah:
Check a Perl reference for printf. It prints out formatted strings, so you can use it to avoid having to calculate the length of your strings.

Umm, I think you've missed the bit about the output having to be centred (or as near as possible to centred) within a ten character "column". That's what I'm calculating above. The -10%s printf specification just left justifies the output within that column, and unless I'm mistaken there's no way of saying "centre this" within printf.

Cheers,
Paul

[Zim]

Code:
#!/usr/bin/perl -w
use strict;
while(<>){
chomp;
my $l=length(); # number of characters in the username
my $pre=int(5-($l+1)/2); # amount of "pre" space
print " "x$pre.$_." "x(10-$pre-$l);
print "\n" unless ($.%3);
}

Paul, I've been a perl hacker for several years, but I find that you never know what you don't know to even look for, so I always look over these snippets to see if I can learn something new...

Just learned about what I'll call "print x times", and about $. Good stuff!

thanks!
Mike

[Paul McCann]

Originally posted by Zim:

Just learned about what I'll call "print x times", and about $. Good stuff!

Nice to know! You're right, useful little worms pop out of the woodwork every now and then: Perl seems to have more nooks and crannies than most languages, which seems to generate sneers from language purists, but smiles from those of us who enjoy a little perversity!

Cheers,
Paul

[Wevah]

Originally posted by Paul McCann:
Umm, I think you've missed the bit about the output having to be centred (or as near as possible to centred) within a ten character "column". That's what I'm calculating above. The -10%s printf specification just left justifies the output within that column, and unless I'm mistaken there's no way of saying "centre this" within printf.

Cheers,
Paul

Yes, you're right, I did. Seems kind of silly to center names in a multicolumn layout (to me) though.

Sorry.

[LordJavac]

Just to enlighten some to a feature of perl, you could also use a format as in:

Code:
#!/usr/bin/perl -w

format STDOUT =
@|||||||||| @|||||||||| @||||||||||
@items
.

while (<>) {
    chomp;
    push @items, $_;

    if (@items == 3) {
        write;
        @items = ();
    }
}
push @items, '' while (@items < 3);
write;

[Paul McCann]

Thanks for the 'format' reminder. It's been many a long year since I used "write" in this way, and I'd forgotten how useful it can be. Anyone looking to make multipage reports in good old ascii should also have a close look at Damian Conway's Text::Reform module, which does similar things to the built in format facility, but with more finesse and more flexibility. Umm, let's just say it's *better* ; (for example, it allows you to use footers easily).

Cheers,
Paul