From: Dark Ambient <sambient@...>
Date: 2006-07-04T01:52:47+09:00
Subject: Re: if problem in loop causing weirdness

Condensed version:

require 'ftools'

Dir.chdir 'C:/testfilesmoved'

require 'ftools'


pic_names = Dir['C:/testfilesorig/*.*']
destdir = Dir['C:/testfilesmoved/*.*']

pics2bmoved = []
pic_names.each do |name|

            puts 'Do you wish to move ' + name + 'file?,"yes" or "no" ?'
               decision = gets.chomp.downcase

                     if decision == 'yes'
                          destdir.each do |x|
                             if File.compare(name, x) == false
                                pics2bmoved.push(name)
                                # problem here, first with loop same as b4, so
                                # i removed the files from destdir, so
File.compare wouldn't hit true
                                # yet, the pics2bmoved.push doesn't
seem to work.

                                else
                                    puts 'The file already exists in
destination, overwrite? "yes" or "no" '
                                        ow = gets.chomp.downcase
                                 if ow == 'yes'
                                     pics2bmoved.push(name)
                                     else
                                        puts 'This ' + name + ' will
not be moved'

                                 end # for ow==yes
                           end # for File.compare
                        end # for destdir loop
                    end # for decision == yes
       end # for pic_names loop

           if pics2bmoved.empty?
               puts
               puts 'No files will be moved'
                     else
                     puts pics2bmoved
          end

On 7/3/06, Dark Ambient <sambient@gmail.com> wrote:
> On 7/3/06, Matthew Smillie <M.B.Smillie@sms.ed.ac.uk> wrote:
>
> > Hmm.  This strikes me as a possible misunderstanding of how nested
> > loops work.  The inner loop (pics2bmoved.each in this case) is
> > executed once for every element in the outer loop (destdir.each).  In
> > a simpler example:
> >
> > a = ['a', 'b', 'c']
> > b = [1, 2, 3]
> > a.each do |letter|
> >    b.each do |number|
> >      puts "#{letter}, #{number}"
> >    end
> > end
> >
> > prints the following:
> > a, 1
> > a, 2
> > a, 3
> > b, 1
> > b, 2
> > b, 3
> > c, 1
> > c, 2
> > c, 3
>
> Excellent illustration, very helpful , though the results are still forthcoming.
>
> > Which seems similar to what I guessed your problem might be.  Are you
> > creating pics2bmoved in a similar sort of nested loop?
>
> pics2bmoved was created using just .push (which was the first section)
> However in section 2, it was the inner loop to the destination
> directory / or outer array.
> This would explain the repeating for the same element.  I've gone
> ahead and am attempting to condense the two sections into one.  I'm
> still faced with the same loop issues though for now.
> > Best of luck,
> > matthew smillie.
>
> Stuart
>
>